matplotlib-users Mailing List for matplotlib (Page 24)

Ok, back from revision...
The is no mix-up for the show command. The only explicit show() command is commented out in line 41. It can be deleted. But I haven't done that, yet. There are several bits of code which are remains of the design process since this is work in progress. Code cleaning will be done when the main functionality is in place.
Back to addmpl where I embedded gui elements into the canvas. Taking out the matplotlib taskbar doesn't change a thing as I wrote earlier, but to make sure it doesn't bother the mainloop, it should be commented out. I may not put it back in, because I don't see the point in needing it. It was just to see if it's possible.
>>But option 2 relinquishes that control to the developer's GUI app. You *cannot* use pyplot for option 2, which is what you are doing. 

Is that so? In line 116 I create the canvas, which is derived from matplotlib's backend's FigureCanvasQTAgg and given to the QWidget at line 119. That's the only part where both interact with each other. the rest is handle by matplotlib. 

The error message says that Axes3D.figure.canvas is 'None' and that's why mouse rotation is disabled.It's None because there is no content at that point, when it's passed to the QWidget. It's filled with content in line 38. So if matplotlib disables the mouse rotation by default, when the canvas is empty how do I prevent this disabling by default? 
If I can't, at what point do I have to pass the filled canvas to the QWidget? How does that impact the GUI itself? 
If I can't enable the mouse rotation by hand and I just can pass filled canvas around, do I have to build a work around with initialize it with an empty 2D canvas and replace it later with the filled 3D canvas? How's the mouse rotation activated then?

In general, I wouldn't have to enable the rotation if it wouldn't be switch off for an empty canvas.
I'm going to consult your book, now, for different ways of coping with such things...
cheers,Christian --
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!" 


     On Tuesday, April 28, 2015 8:28 PM, Benjamin Root <ben...@ou...> wrote:
   

 One thing I see off the bat is your addmpl() method:

```
    def addmpl(self, fig):
        #FigureCanvas.__init__(self, fig)
        self.canvas = FigureCanvas(fig)
        
        Axes3D.mouse_init(self, rotate_btn=1, zoom_btn=2)
        self.mplvl.addWidget(self.canvas)
        self.canvas.draw()
        self.toolbar = NavigationToolbar(self.canvas, self.mplwindow, coordinates=True)
        self.mplvl.addWidget(self.toolbar)
```

You are calling Axes3D.mouse_init() on the Main object (that is `self`). That is completely wrong. It can only be called for the 3d axes objects.

Also, what I see happening here is some mixing up of how to do embedding. There are two approaches to embedding. 1) you can embedded GUI elements into your canvas widget, or 2) you can embed your canvas widget into your GUI app. The important distinction between the two is who controls the mainloop. In option 1 (and in matplotlib in general), pyplot will create the GUI app for you automatically (it is completely transparent to you) and kicks it off upon call to show(). But option 2 relinquishes that control to the developer's GUI app. You *cannot* use pyplot for option 2, which is what you are doing. Rip out all of the pyplot stuff, and instantiate the Qt5 Figure object directly, and then obtain the axes objects from the figure object via calls to add_subplot(). You shouldn't even need to do the whole mouse_init() stuff.

I now think this has nothing to do with Qt Designer. While I don't specifically cover qt5 in my book, I do make all of these distinctions very clear in chapter 5 of my book "Interactive Applications using Matplotlib".

Cheers!
Ben Root


On Tue, Apr 28, 2015 at 4:03 PM, Christian Ambros <am...@ym...> wrote:

Hi Benjamin,
I would do that if my task were my private stuff, but in this case it's work-related and my boss wants me to use the designer and he already set a deadline, which, I already knew, is set to tight. I told him before, that it would be just a try but he sold it to his boss after some pressure. You know how the bosses' bosses are, they don't get the idea that innovation can't be dictated. They don't understand the concept that software is written and doesn't come into existence out of nothing.
Without PyQt5 it's working fine. I got the plots and they are gorgeous, but that doesn't help when presenting to the bosses. If I just would know how to activate the 3d-draw's mouse action again, by hand, than it has to last just some moments for the presentation, afterwards I have the time to examine and find a more robust solution.
Thanks for the effort.cheers,Christian
 --
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!" 


     On Tuesday, April 28, 2015 7:30 PM, Benjamin Root <ben...@ou...> wrote:
   

 I think there is something wrong with the embedding code rather than there being an actual bug. I have embedded mplot3d stuff before (admittedly, not in qt5) with no problems. I haven't had the time yet to examine your code to see what the potential issue is, though. I have also never used Qt designer, so I have no clue if there is something that it is doing that might be making things difficult.

I already know that the code you originally posted has errors in it. I would suggest first making a prototype without Qt Designer as a proof-of-concept, perhaps starting with one of our examples in the gallery?

Ben Root


On Tue, Apr 28, 2015 at 2:12 PM, Christian Ambros <am...@ym...> wrote:

 Since there seems to be no progress with this issue, may I assume there isn't any interest in it?I took a further look around in the internet but couldn't any solution.It leads to an other question: How many users of matplotlib are using 3d-plots anyway? It we are just a few and there won't be anyone who wants to embed it in PyQt5, than I can understand that this issue doesn't concern no-one and I have to look somewhere else to find a 3d-plotting lib which is embedable.
cheers,Christain
--
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!" 


     On Tuesday, April 21, 2015 1:44 PM, Benjamin Root <ben...@ou...> wrote:
   

 The addmpl() method isn't right. You created a canvas object, assigned it to self.canvas, but then tried to call FigureCanvas.__init__(), passing it whatever object "self" is. What class is addmpl() a part of? What does it subclass?

On Tue, Apr 21, 2015 at 7:24 AM, Christian Ambros <am...@ym...> wrote:

Hi,
I embedded Ryan's examble for PyQt5-matplotlib use into my App but I get the following error:
/usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py:1009: UserWarning: Axes3D.figure.canvas is 'None', mouse rotation disabled.  Set canvas then call Axes3D.mouse_init().
  warnings.warn('Axes3D.figure.canvas is \'None\', mouse rotation disabled.  Set canvas then call Axes3D.mouse_init().')

>From Stackoverflow, which host to question about this, I know that mouse actions are disabled when the canvas is re-initialized by whatever.
The only position I do such an operation is in here:    def addmpl(self, fig):
        self.canvas = FigureCanvas(fig)
        #FigureCanvas.__init__(self, fig)
        #Axes3D.mouse_init(self)
        self.mplvl.addWidget(self.canvas)
        self.canvas.draw()
        self.toolbar = NavigationToolbar(self.canvas, self.mplwindow, coordinates=True)
        self.mplvl.addWidget(self.toolbar)
 On of the Stackoverflow suggestion says, that re initializing FigureCanvas should do the trick but I'll get: 

Traceback (most recent call last):
  File "./ex_0.1.py", line 145, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 116, in addmpl
    FigureCanvas.__init__(self, fig)
  File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5agg.py", line 181, in __init__
    FigureCanvasQT.__init__(self, figure)
  File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5.py", line 237, in __init__
    super(FigureCanvasQT, self).__init__(figure=figure)
TypeError: super(type, obj): obj must be an instance or subtype of type

as follow-up error message.
just using Axes3D.mouse_init() , as suggested by matplotlib itself, leads to:
Traceback (most recent call last):
  File "./ex_0.1.py", line 146, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 118, in addmpl
    Axes3D.mouse_init()
TypeError: mouse_init() missing 1 required positional argument: 'self'
adding self leads to:
Traceback (most recent call last):
  File "./ex_0.1.py", line 146, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 118, in addmpl
    Axes3D.mouse_init(self)
  File "/usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py", line 1002, in mouse_init
    canv = self.figure.canvas
AttributeError: 'Main' object has no attribute 'figure'
./ex_0.1.py &

Maybe I'm adding those lines at the wrong place, but I could fined anything useful in the matplotlib documantation, that would help me out, either.
Any thougts that might help?
Cheers,Christian

--
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
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One thing I see off the bat is your addmpl() method:

```
    def addmpl(self, fig):
        #FigureCanvas.__init__(self, fig)
        self.canvas = FigureCanvas(fig)

        Axes3D.mouse_init(self, rotate_btn=1, zoom_btn=2)
        self.mplvl.addWidget(self.canvas)
        self.canvas.draw()
        self.toolbar = NavigationToolbar(self.canvas, self.mplwindow,
coordinates=True)
        self.mplvl.addWidget(self.toolbar)
```

You are calling Axes3D.mouse_init() on the Main object (that is `self`).
That is completely wrong. It can only be called for the 3d axes objects.

Also, what I see happening here is some mixing up of how to do embedding.
There are two approaches to embedding. 1) you can embedded GUI elements
into your canvas widget, or 2) you can embed your canvas widget into your
GUI app. The important distinction between the two is who controls the
mainloop. In option 1 (and in matplotlib in general), pyplot will create
the GUI app for you automatically (it is completely transparent to you) and
kicks it off upon call to show(). But option 2 relinquishes that control to
the developer's GUI app. You *cannot* use pyplot for option 2, which is
what you are doing. Rip out all of the pyplot stuff, and instantiate the
Qt5 Figure object directly, and then obtain the axes objects from the
figure object via calls to add_subplot(). You shouldn't even need to do the
whole mouse_init() stuff.

I now think this has nothing to do with Qt Designer. While I don't
specifically cover qt5 in my book, I do make all of these distinctions very
clear in chapter 5 of my book "Interactive Applications using Matplotlib".

Cheers!
Ben Root


On Tue, Apr 28, 2015 at 4:03 PM, Christian Ambros <am...@ym...> wrote:

> Hi Benjamin,
>
> I would do that if my task were my private stuff, but in this case it's
> work-related and my boss wants me to use the designer and he already set a
> deadline, which, I already knew, is set to tight. I told him before, that
> it would be just a try but he sold it to his boss after some pressure. You
> know how the bosses' bosses are, they don't get the idea that innovation
> can't be dictated. They don't understand the concept that software is
> written and doesn't come into existence out of nothing.
>
> Without PyQt5 it's working fine. I got the plots and they are gorgeous,
> but that doesn't help when presenting to the bosses. If I just would know
> how to activate the 3d-draw's mouse action again, by hand, than it has to
> last just some moments for the presentation, afterwards I have the time to
> examine and find a more robust solution.
>
> Thanks for the effort.
> cheers,
> Christian
>
> --
> "A little learning never caused anyone's head to explode!"
>
>
> "Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
>
>
>
>   On Tuesday, April 28, 2015 7:30 PM, Benjamin Root <ben...@ou...>
> wrote:
>
>
> I think there is something wrong with the embedding code rather than there
> being an actual bug. I have embedded mplot3d stuff before (admittedly, not
> in qt5) with no problems. I haven't had the time yet to examine your code
> to see what the potential issue is, though. I have also never used Qt
> designer, so I have no clue if there is something that it is doing that
> might be making things difficult.
>
> I already know that the code you originally posted has errors in it. I
> would suggest first making a prototype without Qt Designer as a
> proof-of-concept, perhaps starting with one of our examples in the gallery?
>
> Ben Root
>
>
> On Tue, Apr 28, 2015 at 2:12 PM, Christian Ambros <am...@ym...>
> wrote:
>
>  Since there seems to be no progress with this issue, may I assume there
> isn't any interest in it?
> I took a further look around in the internet but couldn't any solution.
> It leads to an other question: How many users of matplotlib are using
> 3d-plots anyway? It we are just a few and there won't be anyone who wants
> to embed it in PyQt5, than I can understand that this issue doesn't concern
> no-one and I have to look somewhere else to find a 3d-plotting lib which is
> embedable.
>
> cheers,
> Christain
> --
> "A little learning never caused anyone's head to explode!"
>
>
> "Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
>
>
>
>   On Tuesday, April 21, 2015 1:44 PM, Benjamin Root <ben...@ou...>
> wrote:
>
>
> The addmpl() method isn't right. You created a canvas object, assigned it
> to self.canvas, but then tried to call FigureCanvas.__init__(), passing it
> whatever object "self" is. What class is addmpl() a part of? What does it
> subclass?
>
> On Tue, Apr 21, 2015 at 7:24 AM, Christian Ambros <am...@ym...>
> wrote:
>
> Hi,
>
> I embedded Ryan's examble for PyQt5-matplotlib use into my App but I get
> the following error:
>
> /usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py:1009:
> UserWarning: Axes3D.figure.canvas is 'None', mouse rotation disabled.  Set
> canvas then call Axes3D.mouse_init().
>   warnings.warn('Axes3D.figure.canvas is \'None\', mouse rotation
> disabled.  Set canvas then call Axes3D.mouse_init().')
>
> From Stackoverflow, which host to question about this, I know that mouse
> actions are disabled when the canvas is re-initialized by whatever.
>
> The only position I do such an operation is in here:
>
>
>
>
>
>
>
> *def addmpl(self, fig):        self.canvas = FigureCanvas(fig)
> #FigureCanvas.__init__(self, fig)        #Axes3D.mouse_init(self)
> self.mplvl.addWidget(self.canvas)        self.canvas.draw()
> self.toolbar = NavigationToolbar(self.canvas, self.mplwindow,
> coordinates=True)        self.mplvl.addWidget(self.toolbar)*
>
> On of the Stackoverflow suggestion says, that re initializing FigureCanvas
> should do the trick but I'll get:
>
> Traceback (most recent call last):
>   File "./ex_0.1.py", line 145, in <module>
>     main(sys.argv)
>   File "./ex_0.1.py", line 53, in main
>     mainwindow.addmpl(fig1)
>   File "./ex_0.1.py", line 116, in addmpl
>     FigureCanvas.__init__(self, fig)
>   File
> "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5agg.py",
> line 181, in __init__
>     FigureCanvasQT.__init__(self, figure)
>   File
> "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5.py",
> line 237, in __init__
>     super(FigureCanvasQT, self).__init__(figure=figure)
> TypeError: super(type, obj): obj must be an instance or subtype of type
>
> as follow-up error message.
>
> just using *Axes3D.mouse_init()* , as suggested by matplotlib itself,
> leads to:
>
> Traceback (most recent call last):
>   File "./ex_0.1.py", line 146, in <module>
>     main(sys.argv)
>   File "./ex_0.1.py", line 53, in main
>     mainwindow.addmpl(fig1)
>   File "./ex_0.1.py", line 118, in addmpl
>     Axes3D.mouse_init()
> TypeError: mouse_init() missing 1 required positional argument: 'self'
>
> adding self leads to:
>
> Traceback (most recent call last):
>   File "./ex_0.1.py", line 146, in <module>
>     main(sys.argv)
>   File "./ex_0.1.py", line 53, in main
>     mainwindow.addmpl(fig1)
>   File "./ex_0.1.py", line 118, in addmpl
>     Axes3D.mouse_init(self)
>   File
> "/usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py",
> line 1002, in mouse_init
>     canv = self.figure.canvas
> AttributeError: 'Main' object has no attribute 'figure'
> ./ex_0.1.py &
>
> Maybe I'm adding those lines at the wrong place, but I could fined
> anything useful in the matplotlib documantation, that would help me out,
> either.
>
> Any thougts that might help?
>
> Cheers,
> Christian
>
> --
> "A little learning never caused anyone's head to explode!"
>
>
> "Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
>
>
> ------------------------------------------------------------------------------
> BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
> Develop your own process in accordance with the BPMN 2 standard
> Learn Process modeling best practices with Bonita BPM through live
> exercises
> http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual-
> event?utm_
> source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>
>
>
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>
>
>
>

Hi Benjamin,
I would do that if my task were my private stuff, but in this case it's work-related and my boss wants me to use the designer and he already set a deadline, which, I already knew, is set to tight. I told him before, that it would be just a try but he sold it to his boss after some pressure. You know how the bosses' bosses are, they don't get the idea that innovation can't be dictated. They don't understand the concept that software is written and doesn't come into existence out of nothing.
Without PyQt5 it's working fine. I got the plots and they are gorgeous, but that doesn't help when presenting to the bosses. If I just would know how to activate the 3d-draw's mouse action again, by hand, than it has to last just some moments for the presentation, afterwards I have the time to examine and find a more robust solution.
Thanks for the effort.cheers,Christian
 --
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!" 


     On Tuesday, April 28, 2015 7:30 PM, Benjamin Root <ben...@ou...> wrote:
   

 I think there is something wrong with the embedding code rather than there being an actual bug. I have embedded mplot3d stuff before (admittedly, not in qt5) with no problems. I haven't had the time yet to examine your code to see what the potential issue is, though. I have also never used Qt designer, so I have no clue if there is something that it is doing that might be making things difficult.

I already know that the code you originally posted has errors in it. I would suggest first making a prototype without Qt Designer as a proof-of-concept, perhaps starting with one of our examples in the gallery?

Ben Root


On Tue, Apr 28, 2015 at 2:12 PM, Christian Ambros <am...@ym...> wrote:

 Since there seems to be no progress with this issue, may I assume there isn't any interest in it?I took a further look around in the internet but couldn't any solution.It leads to an other question: How many users of matplotlib are using 3d-plots anyway? It we are just a few and there won't be anyone who wants to embed it in PyQt5, than I can understand that this issue doesn't concern no-one and I have to look somewhere else to find a 3d-plotting lib which is embedable.
cheers,Christain
--
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!" 


     On Tuesday, April 21, 2015 1:44 PM, Benjamin Root <ben...@ou...> wrote:
   

 The addmpl() method isn't right. You created a canvas object, assigned it to self.canvas, but then tried to call FigureCanvas.__init__(), passing it whatever object "self" is. What class is addmpl() a part of? What does it subclass?

On Tue, Apr 21, 2015 at 7:24 AM, Christian Ambros <am...@ym...> wrote:

Hi,
I embedded Ryan's examble for PyQt5-matplotlib use into my App but I get the following error:
/usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py:1009: UserWarning: Axes3D.figure.canvas is 'None', mouse rotation disabled.  Set canvas then call Axes3D.mouse_init().
  warnings.warn('Axes3D.figure.canvas is \'None\', mouse rotation disabled.  Set canvas then call Axes3D.mouse_init().')

>From Stackoverflow, which host to question about this, I know that mouse actions are disabled when the canvas is re-initialized by whatever.
The only position I do such an operation is in here:    def addmpl(self, fig):
        self.canvas = FigureCanvas(fig)
        #FigureCanvas.__init__(self, fig)
        #Axes3D.mouse_init(self)
        self.mplvl.addWidget(self.canvas)
        self.canvas.draw()
        self.toolbar = NavigationToolbar(self.canvas, self.mplwindow, coordinates=True)
        self.mplvl.addWidget(self.toolbar)
 On of the Stackoverflow suggestion says, that re initializing FigureCanvas should do the trick but I'll get: 

Traceback (most recent call last):
  File "./ex_0.1.py", line 145, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 116, in addmpl
    FigureCanvas.__init__(self, fig)
  File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5agg.py", line 181, in __init__
    FigureCanvasQT.__init__(self, figure)
  File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5.py", line 237, in __init__
    super(FigureCanvasQT, self).__init__(figure=figure)
TypeError: super(type, obj): obj must be an instance or subtype of type

as follow-up error message.
just using Axes3D.mouse_init() , as suggested by matplotlib itself, leads to:
Traceback (most recent call last):
  File "./ex_0.1.py", line 146, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 118, in addmpl
    Axes3D.mouse_init()
TypeError: mouse_init() missing 1 required positional argument: 'self'
adding self leads to:
Traceback (most recent call last):
  File "./ex_0.1.py", line 146, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 118, in addmpl
    Axes3D.mouse_init(self)
  File "/usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py", line 1002, in mouse_init
    canv = self.figure.canvas
AttributeError: 'Main' object has no attribute 'figure'
./ex_0.1.py &

Maybe I'm adding those lines at the wrong place, but I could fined anything useful in the matplotlib documantation, that would help me out, either.
Any thougts that might help?
Cheers,Christian

--
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
------------------------------------------------------------------------------
BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
Develop your own process in accordance with the BPMN 2 standard
Learn Process modeling best practices with Bonita BPM through live exercises
http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_
source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF
_______________________________________________
Matplotlib-users mailing list
Mat...@li...
https://lists.sourceforge.net/lists/listinfo/matplotlib-users





   
------------------------------------------------------------------------------
One dashboard for servers and applications across Physical-Virtual-Cloud
Widest out-of-the-box monitoring support with 50+ applications
Performance metrics, stats and reports that give you Actionable Insights
Deep dive visibility with transaction tracing using APM Insight.
http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
_______________________________________________
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I think there is something wrong with the embedding code rather than there
being an actual bug. I have embedded mplot3d stuff before (admittedly, not
in qt5) with no problems. I haven't had the time yet to examine your code
to see what the potential issue is, though. I have also never used Qt
designer, so I have no clue if there is something that it is doing that
might be making things difficult.

I already know that the code you originally posted has errors in it. I
would suggest first making a prototype without Qt Designer as a
proof-of-concept, perhaps starting with one of our examples in the gallery?

Ben Root


On Tue, Apr 28, 2015 at 2:12 PM, Christian Ambros <am...@ym...> wrote:

>  Since there seems to be no progress with this issue, may I assume there
> isn't any interest in it?
> I took a further look around in the internet but couldn't any solution.
> It leads to an other question: How many users of matplotlib are using
> 3d-plots anyway? It we are just a few and there won't be anyone who wants
> to embed it in PyQt5, than I can understand that this issue doesn't concern
> no-one and I have to look somewhere else to find a 3d-plotting lib which is
> embedable.
>
> cheers,
> Christain
> --
> "A little learning never caused anyone's head to explode!"
>
>
> "Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
>
>
>
>   On Tuesday, April 21, 2015 1:44 PM, Benjamin Root <ben...@ou...>
> wrote:
>
>
> The addmpl() method isn't right. You created a canvas object, assigned it
> to self.canvas, but then tried to call FigureCanvas.__init__(), passing it
> whatever object "self" is. What class is addmpl() a part of? What does it
> subclass?
>
> On Tue, Apr 21, 2015 at 7:24 AM, Christian Ambros <am...@ym...>
> wrote:
>
> Hi,
>
> I embedded Ryan's examble for PyQt5-matplotlib use into my App but I get
> the following error:
>
> /usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py:1009:
> UserWarning: Axes3D.figure.canvas is 'None', mouse rotation disabled.  Set
> canvas then call Axes3D.mouse_init().
>   warnings.warn('Axes3D.figure.canvas is \'None\', mouse rotation
> disabled.  Set canvas then call Axes3D.mouse_init().')
>
> From Stackoverflow, which host to question about this, I know that mouse
> actions are disabled when the canvas is re-initialized by whatever.
>
> The only position I do such an operation is in here:
>
>
>
>
>
>
>
> *def addmpl(self, fig):        self.canvas = FigureCanvas(fig)
> #FigureCanvas.__init__(self, fig)        #Axes3D.mouse_init(self)
> self.mplvl.addWidget(self.canvas)        self.canvas.draw()
> self.toolbar = NavigationToolbar(self.canvas, self.mplwindow,
> coordinates=True)        self.mplvl.addWidget(self.toolbar)*
>
> On of the Stackoverflow suggestion says, that re initializing FigureCanvas
> should do the trick but I'll get:
>
> Traceback (most recent call last):
>   File "./ex_0.1.py", line 145, in <module>
>     main(sys.argv)
>   File "./ex_0.1.py", line 53, in main
>     mainwindow.addmpl(fig1)
>   File "./ex_0.1.py", line 116, in addmpl
>     FigureCanvas.__init__(self, fig)
>   File
> "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5agg.py",
> line 181, in __init__
>     FigureCanvasQT.__init__(self, figure)
>   File
> "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5.py",
> line 237, in __init__
>     super(FigureCanvasQT, self).__init__(figure=figure)
> TypeError: super(type, obj): obj must be an instance or subtype of type
>
> as follow-up error message.
>
> just using *Axes3D.mouse_init()* , as suggested by matplotlib itself,
> leads to:
>
> Traceback (most recent call last):
>   File "./ex_0.1.py", line 146, in <module>
>     main(sys.argv)
>   File "./ex_0.1.py", line 53, in main
>     mainwindow.addmpl(fig1)
>   File "./ex_0.1.py", line 118, in addmpl
>     Axes3D.mouse_init()
> TypeError: mouse_init() missing 1 required positional argument: 'self'
>
> adding self leads to:
>
> Traceback (most recent call last):
>   File "./ex_0.1.py", line 146, in <module>
>     main(sys.argv)
>   File "./ex_0.1.py", line 53, in main
>     mainwindow.addmpl(fig1)
>   File "./ex_0.1.py", line 118, in addmpl
>     Axes3D.mouse_init(self)
>   File
> "/usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py",
> line 1002, in mouse_init
>     canv = self.figure.canvas
> AttributeError: 'Main' object has no attribute 'figure'
> ./ex_0.1.py &
>
> Maybe I'm adding those lines at the wrong place, but I could fined
> anything useful in the matplotlib documantation, that would help me out,
> either.
>
> Any thougts that might help?
>
> Cheers,
> Christian
>
> --
> "A little learning never caused anyone's head to explode!"
>
>
> "Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
>
>
> ------------------------------------------------------------------------------
> BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
> Develop your own process in accordance with the BPMN 2 standard
> Learn Process modeling best practices with Bonita BPM through live
> exercises
> http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual-
> event?utm_
> source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF
> _______________________________________________
> Matplotlib-users mailing list
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>
>
>
>
>
>
> ------------------------------------------------------------------------------
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> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
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>
>

 Since there seems to be no progress with this issue, may I assume there isn't any interest in it?I took a further look around in the internet but couldn't any solution.It leads to an other question: How many users of matplotlib are using 3d-plots anyway? It we are just a few and there won't be anyone who wants to embed it in PyQt5, than I can understand that this issue doesn't concern no-one and I have to look somewhere else to find a 3d-plotting lib which is embedable.
cheers,Christain
--
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!" 


     On Tuesday, April 21, 2015 1:44 PM, Benjamin Root <ben...@ou...> wrote:
   

 The addmpl() method isn't right. You created a canvas object, assigned it to self.canvas, but then tried to call FigureCanvas.__init__(), passing it whatever object "self" is. What class is addmpl() a part of? What does it subclass?

On Tue, Apr 21, 2015 at 7:24 AM, Christian Ambros <am...@ym...> wrote:

Hi,
I embedded Ryan's examble for PyQt5-matplotlib use into my App but I get the following error:
/usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py:1009: UserWarning: Axes3D.figure.canvas is 'None', mouse rotation disabled.  Set canvas then call Axes3D.mouse_init().
  warnings.warn('Axes3D.figure.canvas is \'None\', mouse rotation disabled.  Set canvas then call Axes3D.mouse_init().')

>From Stackoverflow, which host to question about this, I know that mouse actions are disabled when the canvas is re-initialized by whatever.
The only position I do such an operation is in here:    def addmpl(self, fig):
        self.canvas = FigureCanvas(fig)
        #FigureCanvas.__init__(self, fig)
        #Axes3D.mouse_init(self)
        self.mplvl.addWidget(self.canvas)
        self.canvas.draw()
        self.toolbar = NavigationToolbar(self.canvas, self.mplwindow, coordinates=True)
        self.mplvl.addWidget(self.toolbar)
 On of the Stackoverflow suggestion says, that re initializing FigureCanvas should do the trick but I'll get: 

Traceback (most recent call last):
  File "./ex_0.1.py", line 145, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 116, in addmpl
    FigureCanvas.__init__(self, fig)
  File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5agg.py", line 181, in __init__
    FigureCanvasQT.__init__(self, figure)
  File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5.py", line 237, in __init__
    super(FigureCanvasQT, self).__init__(figure=figure)
TypeError: super(type, obj): obj must be an instance or subtype of type

as follow-up error message.
just using Axes3D.mouse_init() , as suggested by matplotlib itself, leads to:
Traceback (most recent call last):
  File "./ex_0.1.py", line 146, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 118, in addmpl
    Axes3D.mouse_init()
TypeError: mouse_init() missing 1 required positional argument: 'self'
adding self leads to:
Traceback (most recent call last):
  File "./ex_0.1.py", line 146, in <module>
    main(sys.argv)
  File "./ex_0.1.py", line 53, in main
    mainwindow.addmpl(fig1)
  File "./ex_0.1.py", line 118, in addmpl
    Axes3D.mouse_init(self)
  File "/usr/local/lib/python3.4/dist-packages/mpl_toolkits/mplot3d/axes3d.py", line 1002, in mouse_init
    canv = self.figure.canvas
AttributeError: 'Main' object has no attribute 'figure'
./ex_0.1.py &

Maybe I'm adding those lines at the wrong place, but I could fined anything useful in the matplotlib documantation, that would help me out, either.
Any thougts that might help?
Cheers,Christian

--
"A little learning never caused anyone's head to explode!"

"Ein wenig Lernen hat noch niemandens Kopf zum Explodieren gebracht!"
------------------------------------------------------------------------------
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Develop your own process in accordance with the BPMN 2 standard
Learn Process modeling best practices with Bonita BPM through live exercises
http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_
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_______________________________________________
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Those look like they are coming up out of numpy.  I am not familiar with
gentoo, but it looks like numpy is not in the dependencies list.

Tom

On Mon, Apr 27, 2015, 16:59 Martin MOKREJŠ <mmo...@gm...> wrote:

> Hi,
>    I use dev-python/matplotlib-1.4.3 and I suspect this is a recent
> regression in it. Can anybody reproduce this?
>
> $ pychecker test.py
> Processing module test (test.py)...
> warning: couldn't find real module for class <class 'fftpack.error'>
> (module name: fftpack)
> warning: couldn't find real module for class <class
> 'lapack_lite.LapackError'> (module name: lapack_lite)
> warning: couldn't find real module for class <type 'mtrand.RandomState'>
> (module name: mtrand)
> warning: couldn't find real module for class <type 'mtrand.RandomState'>
> (module name: mtrand)
>    ImportError: No module named _winreg
> warning: couldn't find real module for class <type 'cntr.Cntr'> (module
> name: cntr)
>
> Warnings...
>
> test.py:3: Imported module (pylab) not used
> $ cat test.py
> #! /usr/bin/python
>
> import pylab
> $
>
>
>
>
>
>
> It was installed with these flags on Gentoo Linux:
>
> # emerge -pv matplotlib
>
> These are the packages that would be merged, in order:
>
> Calculating dependencies... done!
> [ebuild   R    ] dev-python/matplotlib-1.4.3::gentoo  USE="cairo examples
> fltk gtk tk wxwidgets -doc -excel -gtk3 -latex -pyside -qt4 -qt5 {-test}"
> PYTHON_TARGETS="python2_7 -python3_3 -python3_4" 0 KiB
>
>
>
> I use dev-python/pychecker-0.8.19-r1 for the code sanity checks.
> http://pychecker.sourceforge.net/ http://pypi.python.org/pypi/PyChecker
>
>
> Thank you for clues,
> Martin
>
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
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> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

Hi,
   I use dev-python/matplotlib-1.4.3 and I suspect this is a recent regression in it. Can anybody reproduce this?

$ pychecker test.py
Processing module test (test.py)...
warning: couldn't find real module for class <class 'fftpack.error'> (module name: fftpack)
warning: couldn't find real module for class <class 'lapack_lite.LapackError'> (module name: lapack_lite)
warning: couldn't find real module for class <type 'mtrand.RandomState'> (module name: mtrand)
warning: couldn't find real module for class <type 'mtrand.RandomState'> (module name: mtrand)
   ImportError: No module named _winreg
warning: couldn't find real module for class <type 'cntr.Cntr'> (module name: cntr)

Warnings...

test.py:3: Imported module (pylab) not used
$ cat test.py
#! /usr/bin/python

import pylab
$






It was installed with these flags on Gentoo Linux:

# emerge -pv matplotlib

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild   R    ] dev-python/matplotlib-1.4.3::gentoo  USE="cairo examples fltk gtk tk wxwidgets -doc -excel -gtk3 -latex -pyside -qt4 -qt5 {-test}" PYTHON_TARGETS="python2_7 -python3_3 -python3_4" 0 KiB



I use dev-python/pychecker-0.8.19-r1 for the code sanity checks.
http://pychecker.sourceforge.net/ http://pypi.python.org/pypi/PyChecker


Thank you for clues,
Martin

Hi Tom,

Thanks for the reply. I will open it as an issue on github.

Best regards,
Jesper

2015-04-25 22:20 GMT+02:00 Thomas Caswell <tca...@gm...>:

> Jesper,
>
> Can you open an issue on this on github.  If you are feeling ambitious a
> pull request fixing the bug (as you seem to have a good idea of where the
> problem is) would also be great!
>
> Tom
>
> On Fri, Apr 24, 2015 at 8:38 AM Jesper Larsen <jes...@gm...>
> wrote:
>
>> Hi Matplotlib Users,
>>
>> When I make wind barbs with rounding enabled and custom barb increments I
>> noticed that there were no wind barbs with half barbs above 2 full barbs.
>> The reason seems to be a bug in the _find_tails method. The bug is
>> illustrated by this small script (_find_tails is a copy of the one in
>> matplotlib):
>>
>> import numpy as np
>>
>> def _find_tails(self, mag, rounding=True, half=5, full=10, flag=50):
>>     '''
>>     Find how many of each of the tail pieces is necessary.  Flag
>>     specifies the increment for a flag, barb for a full barb, and half for
>>     half a barb. Mag should be the magnitude of a vector (ie. >= 0).
>>
>>     This returns a tuple of:
>>
>>         (*number of flags*, *number of barbs*, *half_flag*, *empty_flag*)
>>
>>     *half_flag* is a boolean whether half of a barb is needed,
>>     since there should only ever be one half on a given
>>     barb. *empty_flag* flag is an array of flags to easily tell if
>>     a barb is empty (too low to plot any barbs/flags.
>>     '''
>>
>>     #If rounding, round to the nearest multiple of half, the smallest
>>     #increment
>>     if rounding:
>>         mag = half * (mag / half + 0.5).astype(np.int)
>>
>>     num_flags = np.floor(mag / flag).astype(np.int)
>>     mag = np.mod(mag, flag)
>>
>>     num_barb = np.floor(mag / full).astype(np.int)
>>     mag = np.mod(mag, full)
>>
>>     half_flag = mag >= half
>>     empty_flag = ~(half_flag | (num_flags > 0) | (num_barb > 0))
>>
>>     return num_flags, num_barb, half_flag, empty_flag
>>
>> def main():
>>     mag = np.arange(0,21,1)
>>     barb_incs = {'half': 2.57222,
>>                  'full': 5.14444,
>>                  'flag': 25.7222}
>>     print 'With rounding'
>>     num_flags, num_barb, half_flag, empty_flag =  _find_tails(None, mag,
>> rounding=True, **barb_incs)
>>     for i in range(len(mag)):
>>         print mag[i], num_flags[i], num_barb[i], half_flag[i],
>> empty_flag[i]
>>     print 'Without rounding'
>>     num_flags, num_barb, half_flag, empty_flag =  _find_tails(None, mag,
>> rounding=False, **barb_incs)
>>     for i in range(len(mag)):
>>         print mag[i], num_flags[i], num_barb[i], half_flag[i],
>> empty_flag[i]
>>
>> if __name__ == '__main__':
>>     exit(main())
>>
>> It seems like the error is not present when the barb increments are not
>> set. I believe the reason for the bug is the float comparison (half_flag =
>> mag >= half) where the value is rounded to a value very close to/identical
>> to the 'half' increment. And it seems like python does the right thing when
>> the "half" increment is a whole number but not always when it is not.
>>
>> But in any case the code should probably not depend two floats being
>> equal.
>>
>> Best regards,
>> Jesper
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
>> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>
>

Jesper,

Can you open an issue on this on github.  If you are feeling ambitious a
pull request fixing the bug (as you seem to have a good idea of where the
problem is) would also be great!

Tom

On Fri, Apr 24, 2015 at 8:38 AM Jesper Larsen <jes...@gm...>
wrote:

> Hi Matplotlib Users,
>
> When I make wind barbs with rounding enabled and custom barb increments I
> noticed that there were no wind barbs with half barbs above 2 full barbs.
> The reason seems to be a bug in the _find_tails method. The bug is
> illustrated by this small script (_find_tails is a copy of the one in
> matplotlib):
>
> import numpy as np
>
> def _find_tails(self, mag, rounding=True, half=5, full=10, flag=50):
>     '''
>     Find how many of each of the tail pieces is necessary.  Flag
>     specifies the increment for a flag, barb for a full barb, and half for
>     half a barb. Mag should be the magnitude of a vector (ie. >= 0).
>
>     This returns a tuple of:
>
>         (*number of flags*, *number of barbs*, *half_flag*, *empty_flag*)
>
>     *half_flag* is a boolean whether half of a barb is needed,
>     since there should only ever be one half on a given
>     barb. *empty_flag* flag is an array of flags to easily tell if
>     a barb is empty (too low to plot any barbs/flags.
>     '''
>
>     #If rounding, round to the nearest multiple of half, the smallest
>     #increment
>     if rounding:
>         mag = half * (mag / half + 0.5).astype(np.int)
>
>     num_flags = np.floor(mag / flag).astype(np.int)
>     mag = np.mod(mag, flag)
>
>     num_barb = np.floor(mag / full).astype(np.int)
>     mag = np.mod(mag, full)
>
>     half_flag = mag >= half
>     empty_flag = ~(half_flag | (num_flags > 0) | (num_barb > 0))
>
>     return num_flags, num_barb, half_flag, empty_flag
>
> def main():
>     mag = np.arange(0,21,1)
>     barb_incs = {'half': 2.57222,
>                  'full': 5.14444,
>                  'flag': 25.7222}
>     print 'With rounding'
>     num_flags, num_barb, half_flag, empty_flag =  _find_tails(None, mag,
> rounding=True, **barb_incs)
>     for i in range(len(mag)):
>         print mag[i], num_flags[i], num_barb[i], half_flag[i],
> empty_flag[i]
>     print 'Without rounding'
>     num_flags, num_barb, half_flag, empty_flag =  _find_tails(None, mag,
> rounding=False, **barb_incs)
>     for i in range(len(mag)):
>         print mag[i], num_flags[i], num_barb[i], half_flag[i],
> empty_flag[i]
>
> if __name__ == '__main__':
>     exit(main())
>
> It seems like the error is not present when the barb increments are not
> set. I believe the reason for the bug is the float comparison (half_flag =
> mag >= half) where the value is rounded to a value very close to/identical
> to the 'half' increment. And it seems like python does the right thing when
> the "half" increment is a whole number but not always when it is not.
>
> But in any case the code should probably not depend two floats being equal.
>
> Best regards,
> Jesper
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

Hi,

I think there is a good reason to add the functionality to plot
pre-computed histograms to hist() or to a new function with similar API.

Sometimes histograms are heavy or we don't want to recompute them to
perform a series of plots.

In this case, I miss the ability to easily set the plot style. hist()
allows to chose between bar, step and stepfilled. To change the style with
pre-computed histograms, I need to write 3 different "plots" using bar(),
plot() and fill_between() respectively. This is quite inconvenient and
error prone, considering that these function have different API for the
input data.

Maybe the plotting part of hist() should be splitted in a standalone
function (plotbins() ?)
In this way, hist() can call this function to generate the plot, but also
the user can call it when the histogram is pre-computed. The bonus is that
we retain the same API for plot style.

My 2cents,
Antonio


On Fri, Apr 24, 2015 at 4:31 AM, Jerzy Karczmarczuk <
jer...@un...> wrote:

>
> Le 24/04/2015 12:58, Christian Alis responds to the problem posed by
> Virgil Stokes
> > I had the same problem some time ago and what I did is to use bar() to
> > plot the histogram, which can be done in one line:
> >
> > hst, bin_edges = np.histogram(data)
> > plt.bar(bin_edges[:-1], hst)
> >
> > Perhaps this trick can be added in the documentation?
> >
> > I am willing to code Virgil's request if many will find this useful.
> Separating the computation of the histogram, and plotting it is
> obviously useful.
> (I needed this in a linguistical simulation context, where plotting had
> no sense).
>
> Actually hist is more or less this,
> see _axes.py, line 5678, the Axes method hist just calls
> numpy.histogram. And then plots bars (or uses some other style).
>
> So, although completing the documentation might be of general interest,
> I would NOT recommend adding some new version of hist.
> This would be misleading. Hist is hist is hist(ogram). It computes the
> histogram (and eventually plots it). If it is already computed elsewhere,
> naming  the procedure which JUST plots some bars a "histogram" is
> methodologically very dubious.
>
> Jerzy Karczmarczuk
>
>
>
> ------------------------------------------------------------------------------
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Hi Matplotlib Users,

When I make wind barbs with rounding enabled and custom barb increments I
noticed that there were no wind barbs with half barbs above 2 full barbs.
The reason seems to be a bug in the _find_tails method. The bug is
illustrated by this small script (_find_tails is a copy of the one in
matplotlib):

import numpy as np

def _find_tails(self, mag, rounding=True, half=5, full=10, flag=50):
    '''
    Find how many of each of the tail pieces is necessary.  Flag
    specifies the increment for a flag, barb for a full barb, and half for
    half a barb. Mag should be the magnitude of a vector (ie. >= 0).

    This returns a tuple of:

        (*number of flags*, *number of barbs*, *half_flag*, *empty_flag*)

    *half_flag* is a boolean whether half of a barb is needed,
    since there should only ever be one half on a given
    barb. *empty_flag* flag is an array of flags to easily tell if
    a barb is empty (too low to plot any barbs/flags.
    '''

    #If rounding, round to the nearest multiple of half, the smallest
    #increment
    if rounding:
        mag = half * (mag / half + 0.5).astype(np.int)

    num_flags = np.floor(mag / flag).astype(np.int)
    mag = np.mod(mag, flag)

    num_barb = np.floor(mag / full).astype(np.int)
    mag = np.mod(mag, full)

    half_flag = mag >= half
    empty_flag = ~(half_flag | (num_flags > 0) | (num_barb > 0))

    return num_flags, num_barb, half_flag, empty_flag

def main():
    mag = np.arange(0,21,1)
    barb_incs = {'half': 2.57222,
                 'full': 5.14444,
                 'flag': 25.7222}
    print 'With rounding'
    num_flags, num_barb, half_flag, empty_flag =  _find_tails(None, mag,
rounding=True, **barb_incs)
    for i in range(len(mag)):
        print mag[i], num_flags[i], num_barb[i], half_flag[i], empty_flag[i]
    print 'Without rounding'
    num_flags, num_barb, half_flag, empty_flag =  _find_tails(None, mag,
rounding=False, **barb_incs)
    for i in range(len(mag)):
        print mag[i], num_flags[i], num_barb[i], half_flag[i], empty_flag[i]

if __name__ == '__main__':
    exit(main())

It seems like the error is not present when the barb increments are not
set. I believe the reason for the bug is the float comparison (half_flag =
mag >= half) where the value is rounded to a value very close to/identical
to the 'half' increment. And it seems like python does the right thing when
the "half" increment is a whole number but not always when it is not.

But in any case the code should probably not depend two floats being equal.

Best regards,
Jesper

Le 24/04/2015 12:58, Christian Alis responds to the problem posed by 
Virgil Stokes
> I had the same problem some time ago and what I did is to use bar() to
> plot the histogram, which can be done in one line:
>
> hst, bin_edges = np.histogram(data)
> plt.bar(bin_edges[:-1], hst)
>
> Perhaps this trick can be added in the documentation?
>
> I am willing to code Virgil's request if many will find this useful.
Separating the computation of the histogram, and plotting it is 
obviously useful.
(I needed this in a linguistical simulation context, where plotting had 
no sense).

Actually hist is more or less this,
see _axes.py, line 5678, the Axes method hist just calls 
numpy.histogram. And then plots bars (or uses some other style).

So, although completing the documentation might be of general interest, 
I would NOT recommend adding some new version of hist.
This would be misleading. Hist is hist is hist(ogram). It computes the 
histogram (and eventually plots it). If it is already computed elsewhere,
naming  the procedure which JUST plots some bars a "histogram" is 
methodologically very dubious.

Jerzy Karczmarczuk

On 24-Apr-2015 12:58, Christian Alis wrote:
> I had the same problem some time ago and what I did is to use bar() to
> plot the histogram, which can be done in one line:
>
> hist, bin_edges = np.histogram(data)
> plt.bar(bin_edges[:-1], hist)
Very elegant Christian :-)
>
> Perhaps this trick can be added in the documentation?
Well, I vote to add it. However, I did find the following nice example (after 
reading your email) that shows how the bar function might be used 
(http://matplotlib.org/examples/api/barchart_demo.html) for my problem. Had I 
seen this before, I probably would not have posted this request.:-[
>
> I am willing to code Virgil's request if many will find this useful.
>
>
> On Fri, Apr 24, 2015 at 11:33 AM, Virgil Stokes <vs...@it...> wrote:
>> I have some Python (2.7.9) code that processes some rather large data sets
>> to determine the curvatures along 2D curves. One feature of these data that
>> I like to look at is the distribution of the curvatures. I use NumPy to to
>> determine histograms for each set, and save the histogram parameters
>> returned from numpy.histogram in a file.
>>
>> I would like to use Matplotlib to plot histograms from the parameters
>> returned in NumPy and stored in a file --- why? Because the size of my data
>> sets does not allow for the use of the histogram plot function in Matplotlib
>> (1.4.3); i.e., it needs the data sets to calculate the histogram, before
>> doing the plot. I would like to have a histogram plot function in Matplotlib
>> that could bypass the actual calculation of the bin counts and edges from
>> the data, and use values of these found a priori. Of course, an obvious
>> question is -- Why not write code to plot the rectangles yourself? Yes, I
>> could do this; but, why not extend the Matplotlib histogram class to allow
>> for this option? If I better understood Matplotlib, I would try this myself.
>> Maybe it is possible to get this into the next planned release (1.5). :-)
>>
>> If this request is inappropriate for this list, then please accept my
>> apology and direct me to where I should send this request.
>>
>> Best regards.
>>
>> ------------------------------------------------------------------------------
>> One dashboard for servers and applications across Physical-Virtual-Cloud
>> Widest out-of-the-box monitoring support with 50+ applications
>> Performance metrics, stats and reports that give you Actionable Insights
>> Deep dive visibility with transaction tracing using APM Insight.
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>>
Keep up the good work on Matplotlib and I look forward to vers. 1.5 :-)

I had the same problem some time ago and what I did is to use bar() to
plot the histogram, which can be done in one line:

hist, bin_edges = np.histogram(data)
plt.bar(bin_edges[:-1], hist)

Perhaps this trick can be added in the documentation?

I am willing to code Virgil's request if many will find this useful.


On Fri, Apr 24, 2015 at 11:33 AM, Virgil Stokes <vs...@it...> wrote:
> I have some Python (2.7.9) code that processes some rather large data sets
> to determine the curvatures along 2D curves. One feature of these data that
> I like to look at is the distribution of the curvatures. I use NumPy to to
> determine histograms for each set, and save the histogram parameters
> returned from numpy.histogram in a file.
>
> I would like to use Matplotlib to plot histograms from the parameters
> returned in NumPy and stored in a file --- why? Because the size of my data
> sets does not allow for the use of the histogram plot function in Matplotlib
> (1.4.3); i.e., it needs the data sets to calculate the histogram, before
> doing the plot. I would like to have a histogram plot function in Matplotlib
> that could bypass the actual calculation of the bin counts and edges from
> the data, and use values of these found a priori. Of course, an obvious
> question is -- Why not write code to plot the rectangles yourself? Yes, I
> could do this; but, why not extend the Matplotlib histogram class to allow
> for this option? If I better understood Matplotlib, I would try this myself.
> Maybe it is possible to get this into the next planned release (1.5). :-)
>
> If this request is inappropriate for this list, then please accept my
> apology and direct me to where I should send this request.
>
> Best regards.
>
> ------------------------------------------------------------------------------
> One dashboard for servers and applications across Physical-Virtual-Cloud
> Widest out-of-the-box monitoring support with 50+ applications
> Performance metrics, stats and reports that give you Actionable Insights
> Deep dive visibility with transaction tracing using APM Insight.
> http://ad.doubleclick.net/ddm/clk/290420510;117567292;y
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

I have some Python (2.7.9) code that processes some rather large data sets to 
determine the curvatures along 2D curves. One feature of these data that I like 
to look at is the distribution of the curvatures. I use NumPy to to determine 
histograms for each set, and save the histogram parameters returned from 
numpy.histogram in a file.

I would like to use Matplotlib to plot histograms *from the parameters returned 
in NumPy* and stored in a file --- why? Because the size of my data sets does 
not allow for the use of the histogram plot function in Matplotlib (1.4.3); 
i.e., it needs the data sets to calculate the histogram, before doing the plot. 
I would like to have a histogram plot function in Matplotlib that could bypass 
the actual calculation of the bin counts and edges from the data, and use values 
of these found /a priori/. Of course, an obvious question is -- Why not write 
code to plot the rectangles yourself? Yes, I could do this; but, why not extend 
the Matplotlib histogram class to allow for this option? If I better understood 
Matplotlib, I would try this myself. Maybe it is possible to get this into the 
next planned release (1.5).:-)

If this request is inappropriate for this list, then please accept my apology 
and direct me to where I should send this request.

Best regards.

On 23-Apr-2015 20:09, Jerzy Karczmarczuk wrote:
> Animation problem of Virgil Stokes.
>
> Since I began the answer sequence, here's a little more. If this overlaps 
> other answers, I apologize.
>
> About the third parameter
>>> "/frames/ can be a generator, an iterable, or a number of frames."
>> This makes very little sense to me --- what does "or a number of frames" mean?
>>> The name "data_gen" could suggest its meaning (after having read the doc). 
>> I am not sure what you are referencing as "the doc"; but I did read the 
>> documentation several times and English is my native language.
> I am not trying to accuse you of anything, I simply underline that if the 
> documentation - as cited - mentions the word *generator*, and the program 
> contains the argument *data_gen*, which is OBVIOUSLY a generator which 
> *yields* some data, then this might have give you some clues concerning its 
> meaning.
Ok Jerzy --- I apologize for my reaction and you are correct, I should have 
taken "generator" more seriously.
>
>>> Note please that the keyword parameters are specified extra.
>> I am aware of this.  Perhaps, I am a Python dummy --- when I see something 
>> like value = None in a Python API argument, I interpret this as a keyword 
>> argument and not a generator.
>
> 1. Generators might be or not function arguments, keyword or not; this is not 
> an issue here. Generators are entities which produce iterators.  Here you 
> have: *def data_gen(): while True: yield np.random.rand(10)* , and this is all.
Yes, again Jerzy.
>
> 2. When you see "frames=None", etc., this doesn't absolutely mean that it is a 
> kw parameter, just a positional parameter with a default value.
> Brendan Barnwell commented this already.
> If you look at the definition of the FuncAnimation class, which is readable, 
> in the file ... matplotlib/animation.py, you will see
> *def __init__(self, fig, func, frames=None, init_func=None, fargs=None, 
> save_count=None, **kwargs):**
> **   ...*
> which explicitly confirms this.
>
> I think that you got the answers you demanded. The FuncAnimation callback 
> *requires* one argument, even if you don't use it. It may be the frame number 
> (or index if you wish), or explicit, specific data, such as in your first 
> example.
> If, as in your second example, the parameter passed is the frame index, and 
> you want to see how you can use it, test this:
>
> *x=np.linspace(0,20,300)***
>
> *   def update(i):*
>
> **
>
> **
>
> *    data=(np.sin(x+i/3)+1)/2*
>
> **
>
> *    line.set_ydata(data)*
>
> **
>
> *
> *
>
> *ani = animation.FuncAnimation(fig, update, interval=40)*
>
>
> You should see a moving sinusoid.
Yes, I have written something like this myself in an attempt to better 
understand Matplotlib animation. IMHO, the documentation for FuncAnimation 
should explicitly state that one argument is required for the animation 
function. The documentation does state:

   "Makes an animation by repeatedly calling a function /func/, passing in 
(optional) arguments in /fargs/."

But of course this is my opinion.
>
>>>
>>> Please, in such cases test your programs by adding some simple tracing 
>>> contraptions, say, print(data) inside update.
>> I did this and more before posting my email. I would not have posted this 
>> unless I thought it was necessary. And I thought one purpose of this user 
>> group was to help people --- even if they ask a question which may be 
>> annoying or "stupid" in some subscribers opinion. I try to remember what a 
>> very wise teacher once said --- "there is no such thing as a stupid question".
>
> I don't understand your reaction.  I teach computer science for many years, 
> and several times per week I suggest to my students to do this, to trace their 
> programs. I trace mine. 
I have also taught programming and I often make the same suggestion and of 
course this is a suggestion that I follow myself. And I did this before posting. 
One thing that led me astray was the error message that was generated when I 
removed the argument to the animate function. I even went into the source of 
Matplotlib in an attempt to answer this; but, I still could not resolve this issue.
> Nobody feels offended. You said: data is undefined. But it WAS DEFINED, you 
> agree? So, printing its value was the most natural suggestion. You would 
> immediately see that it had been generated by data_gen.
Yes, I did see this and this was one thing that confused me.
>
> Also, I recommend that you look upon the sources of Matplotlib from time to 
> time. I do it regularly, it is nicely commented, and complements very well the 
> documentation.
I have done this several times; but, I find this package very complex and 
difficult to unravel. I use Matplotlib a lot and it is a fantastic package --- 
great work by the developer team. The fact that I do not always need to know 
what is "under the cover" of Matplotlib, is IMHO a positive thing, and a good 
indicator that the documentation (including the examples and gallery) is rather 
well done.
>
> Jerzy Karczmarczuk
>
> PS. Some blizzard around positional/keyword parameters in Python is quite 
> persistent.  "Dive into Python" of Mark Pilgrim covers this, and offers some 
> useful references.
I recently obtained this book; but, have not "dived" into it yet  It now seems 
clear that I should take the plunge soon :-)

Best regards, and thanks for your follow-up Jerzy,
--V

Animation problem of Virgil Stokes.

Since I began the answer sequence, here's a little more. If this 
overlaps other answers, I apologize.

About the third parameter
>> "/frames/ can be a generator, an iterable, or a number of frames."
> This makes very little sense to me --- what does "or a number of 
> frames" mean?
>> The name "data_gen" could suggest its meaning (after having read the 
>> doc). 
> I am not sure what you are referencing as "the doc"; but I did read 
> the documentation several times and English is my native language.
I am not trying to accuse you of anything, I simply underline that if 
the documentation - as cited - mentions the word *generator*, and the 
program contains the argument *data_gen*, which is OBVIOUSLY a generator 
which *yields* some data, then this might have give you some clues 
concerning its meaning.

>> Note please that the keyword parameters are specified extra.
> I am aware of this.  Perhaps, I am a Python dummy --- when I see 
> something like value = None in a Python API argument, I interpret this 
> as a keyword argument and not a generator.

1. Generators might be or not function arguments, keyword or not; this 
is not an issue here. Generators are entities which produce iterators.  
Here you have: *def data_gen(): while True: yield np.random.rand(10)* , 
and this is all.

2. When you see "frames=None", etc., this doesn't absolutely mean that 
it is a kw parameter, just a positional parameter with a default value.
Brendan Barnwell commented this already.
If you look at the definition of the FuncAnimation class, which is 
readable, in the file ... matplotlib/animation.py, you will see
*def __init__(self, fig, func, frames=None, init_func=None, fargs=None, 
save_count=None, **kwargs):**
**   ...*
which explicitly confirms this.

I think that you got the answers you demanded. The FuncAnimation 
callback *requires* one argument, even if you don't use it. It may be 
the frame number (or index if you wish), or explicit, specific data, 
such as in your first example.
If, as in your second example, the parameter passed is the frame index, 
and you want to see how you can use it, test this:

*x=np.linspace(0,20,300)***

*   def update(i):*

**

**

*    data=(np.sin(x+i/3)+1)/2*

**

*    line.set_ydata(data)*

**

***
***

*ani = animation.FuncAnimation(fig, update, interval=40)*


You should see a moving sinusoid.

>>
>> Please, in such cases test your programs by adding some simple 
>> tracing contraptions, say, print(data) inside update.
> I did this and more before posting my email. I would not have posted 
> this unless I thought it was necessary. And I thought one purpose of 
> this user group was to help people --- even if they ask a question 
> which may be annoying or "stupid" in some subscribers opinion. I try 
> to remember what a very wise teacher once said --- "there is no such 
> thing as a stupid question".

I don't understand your reaction.  I teach computer science for many 
years, and several times per week I suggest to my students to do this, 
to trace their programs. I trace mine. Nobody feels offended. You said: 
data is undefined. But it WAS DEFINED, you agree? So, printing its value 
was the most natural suggestion. You would immediately see that it had 
been generated by data_gen.

Also, I recommend that you look upon the sources of Matplotlib from time 
to time. I do it regularly, it is nicely commented, and complements very 
well the documentation.

Jerzy Karczmarczuk

PS. Some blizzard around positional/keyword parameters in Python is 
quite persistent.  "Dive into Python" of Mark Pilgrim covers this, and 
offers some useful references.

See also this : https://www.python.org/dev/peps/pep-3102/

"Thanks for this also Ben --- I will quite likely get this book. However,
considering the complexity of Matplotlib --- only 174 pages bothers me a
little. :-)"

I am just that good!  No, really though, the book focuses only on a subset
of features in Matplotlib, and it does assume that you are somewhat
comfortable with the language (or at least, understand the basics of Object
Oriented Programming and terminology). There will be another book that will
come out in a few months that is intended to be a complete refresh of
Sandro Toshi's 2009 book that might be more up your alley, but I don't know
how much it will cover of Animations. Sandro's book was released before the
animation module was even a twinkle in Ryan May's eye...

Cheers!
Ben Root


On Thu, Apr 23, 2015 at 1:40 PM, Virgil Stokes <vs...@it...> wrote:

>  On 23-Apr-2015 18:48, Benjamin Root wrote:
>
>  ... keeping conversation on-list ...
>
>  The reason why you get that error is because you took out the argument
> from the call signature. But, FuncAnimation assumes that it can send in at
> least one argument. That argument is not optional, even if you aren't using
> it. So, animate() was called with an argument by FuncAnimation internally,
> but since animate() as defined by you did not have that argument, it fails.
>
> Ok --- thanks again for the clarification. Who knows, with a little help
> from this list, I might someday be able to create some useful animations
> with Matplotlib ;-)
>
>
>  Cheers!
> Ben Root
>
>
> On Thu, Apr 23, 2015 at 12:32 PM, Virgil Stokes <vs...@it...> wrote:
>
>>  On 23-Apr-2015 18:25, Benjamin Root wrote:
>>
>>   The documentation should say "the number", not "a number". This
>> particular argument expects either a generator, an iterable, or an integer.
>> If none is given, it will try and figure out something for itself. The
>> integer is used to create a number generator, and so you effectively have
>> an iterable that supplies the first argument to the animation function.
>>
>>  Ok Benjamin :-)   --- thanks for the clarification.
>>
>>
>>  Often times, the first argument to this function is just a frame index.
>> It is quite possible that you don't need it at all, but it is a part of the
>> defined API that the FuncAnimation assumes to be able to call the
>> user-supplied function.
>>
>>  Does that help?
>>
>>  Yes, this does indeed help. But I am still puzzled by the error message
>> given when I remove the argument to the animate function.
>>
>>
>>  Ben Root
>>
>>  <shameless_plug>
>>  P.S. - My new book "Interactive Applications using Matplotlib" has an
>> entire chapter devoted to animations
>>  </shameless_plug>
>>
>>    Thanks for this also Ben --- I will quite likely get this book.
> However, considering the complexity of Matplotlib --- only 174 pages
> bothers me a little. :-)
>
>
>>
>> On Thu, Apr 23, 2015 at 12:05 PM, Virgil Stokes <vs...@it...> wrote:
>>
>>>  Thanks for your reply to my post, Jerzy.
>>>
>>> On 23-Apr-2015 13:18, Jerzy Karczmarczuk wrote:
>>>
>>>
>>>
>>> Le 23/04/2015 12:22, Virgil Stokes a écrit :
>>>
>>> The following interesting example (random_data.py) is posted at:
>>>
>>> http://matplotlib.org/1.4.2/examples/animation/random_data.html
>>>
>>>
>>> import matplotlib.pyplot as plt
>>> import matplotlib.animation as animation
>>>
>>> import numpy as np
>>>
>>>   Yes, I forgot to include this
>>>
>>>
>>> fig, ax = plt.subplots()
>>> line, = ax.plot(np.random.rand(10))
>>> ax.set_ylim(0, 1)
>>>
>>> def update(data):
>>>     line.set_ydata(data)
>>>     return line,
>>>
>>> def data_gen():
>>>     while True: yield np.random.rand(10)
>>>
>>> ani = animation.FuncAnimation(fig, update, data_gen, interval=100)
>>> plt.show()
>>>
>>> This codes works; but, I am very confused by it. For example:
>>>
>>> 1. There are 3 positional arguments given for animation.FuncAnimation;
>>> but, in the
>>> API documentation for this class (
>>> <http://matplotlib.org/api/animation_api.html>
>>> http://matplotlib.org/api/animation_api.html), only
>>> two positional arguments are shown.
>>>
>>> The third one is the third one,
>>> "*frames* can be a generator, an iterable, or a number of frames."
>>>
>>>  This makes very little sense to me --- what does "or a number of
>>> frames" mean?
>>>
>>> The name "data_gen" could suggest its meaning (after having read the
>>> doc).
>>>
>>>  I am not sure what you are referencing as "the doc"; but I did read the
>>> documentation several times and English is my native language.
>>>
>>> Note please that the keyword parameters are specified extra.
>>>
>>>  I am aware of this.  Perhaps, I am a Python dummy --- when I see
>>> something like value = None in a Python API argument, I interpret this as a
>>> keyword argument and not a generator.
>>>
>>>
>>>  2. data, the argument to the update function seems to be undefined.
>>>
>>> FuncAnimation usually passes the frame number: 0, 1, 2, ... as the first
>>> parameter of the update function, when "frames" is None, or the number of
>>> frames. If - as here - the third parameter is a generator, it passes the
>>> yielded data to update.
>>>  It may be used or not.
>>>
>>>  Ok, I understand that better now. But, you say "or *the number* of
>>> frames" but the documentation reads "or *a number* of frames" --- what
>>> does this mean?
>>>
>>> And I still do not understand how to use the first argument of the
>>> function to be called for the animation. In another animation example (
>>> histogram.py), the animation function is defined by:
>>>
>>> def animate(i):
>>>     # simulate new data coming in
>>>     data = np.random.randn(1000
>>>     n, bins = np.histogram(data, 100)
>>>     top = bottom + n
>>>     verts[1::5,1] = top
>>>     verts[2::5,1] = top
>>>
>>> This works of course; but, why is the "i" required? There is no other
>>> reference to it in the entire script. If I remove it; i.e. use def
>>> animate(): I get the following error:
>>>
>>> TypeError: animate() takes no arguments (1 given)
>>>
>>> I do not understand how this explains the fact that the function no
>>> longer has any arguments. Please explain the meaning of this error message?
>>>
>>>
>>> Please, in such cases test your programs by adding some simple tracing
>>> contraptions, say, print(data) inside update.
>>>
>>>  I did this and more before posting my email. I would not have posted
>>> this unless I thought it was necessary. And I thought one purpose of this
>>> user group was to help people --- even if they ask a question which may be
>>> annoying or "stupid" in some subscribers opinion. I try to remember what a
>>> very wise teacher once said --- "there is no such thing as a stupid
>>> question".
>>>
>>>
>>> ------------------------------------------------------------------------------
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>>> Develop your own process in accordance with the BPMN 2 standard
>>> Learn Process modeling best practices with Bonita BPM through live
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>>>
>>>
>>
>>
>
>

On 23-Apr-2015 18:28, Thomas Caswell wrote:
> Can everyone please bring the level of snark/hostility down?  Programming is 
> frustrating, but antagonizing the mailing list does not help anyone.
>
> It is not well documented, but the signature for `func` is assumed to be `def 
> function(required, *optional_positional)` see 
> https://github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/animation.py#L1107 
>
This was very useful!
> for the line where it actually gets called.  The logic behind this is that the 
> function needs to have some input to know what to draw (so the state about 
> where in the sequence you are lives in the animation code, not in the supplied 
> user code).
>
> For passing in the frame data you have several options.  The first is to pass 
> in an iterable of the data you want to be passed to the function (ex 
> np.arange(5), image_stack, image_generator), basically anything where `it = 
> iter(input); data = next(it)` 'does the right thing'.  The second is to pass 
> in a callable where repeated calls to `data = my_callable()` 'does the right 
> thing'  This would be useful if you want to reach out and hit some external 
> hardware for you data each time the animation updates.  The last is to pass in 
> a number of frames, which gets converted into xrange(frames).  In all cases, 
> the Animation turns what ever your input is into an iterable which gets hit 
> once pre frame (see 
> https://github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/animation.py#L1047 
>
And also very useful!
> for the code version of this paragraph).
>
> Tom
>
> PS was finishing this up as Ben's email came in
>
> On Thu, Apr 23, 2015 at 12:06 PM Virgil Stokes <vs...@it... 
> <mailto:vs...@it...>> wrote:
>
>     Thanks for your reply to my post, Jerzy.
>
>
>     On 23-Apr-2015 13:18, Jerzy Karczmarczuk wrote:
>>
>>
>>     Le 23/04/2015 12:22, Virgil Stokes a écrit :
>>>     The following interesting example (random_data.py) is posted at:
>>>
>>>     http://matplotlib.org/1.4.2/examples/animation/random_data.html
>>>
>>>
>>>     import matplotlib.pyplot as plt
>>>     import matplotlib.animation as animation
>>     import numpy as np
>     Yes, I forgot to include this
>
>>>
>>>     fig, ax = plt.subplots()
>>>     line, = ax.plot(np.random.rand(10))
>>>     ax.set_ylim(0, 1)
>>>
>>>     def update(data):
>>>         line.set_ydata(data)
>>>         return line,
>>>
>>>     def data_gen():
>>>         while True: yield np.random.rand(10)
>>>
>>>     ani = animation.FuncAnimation(fig, update, data_gen, interval=100)
>>>     plt.show()
>>>
>>>     This codes works; but, I am very confused by it. For example:
>>>
>>>     1. There are 3 positional arguments given for animation.FuncAnimation;
>>>     but, in the
>>>     API documentation for this class
>>>     (http://matplotlib.org/api/animation_api.html), only
>>>     two positional arguments are shown.
>>     The third one is the third one,
>>     "/frames/ can be a generator, an iterable, or a number of frames."
>     This makes very little sense to me --- what does "or a number of frames" mean?
>
>>     The name "data_gen" could suggest its meaning (after having read the doc). 
>     I am not sure what you are referencing as "the doc"; but I did read the
>     documentation several times and English is my native language.
>
>>     Note please that the keyword parameters are specified extra.
>     I am aware of this. Perhaps, I am a Python dummy --- when I see something
>     like value = None in a Python API argument, I interpret this as a keyword
>     argument and not a generator.
>>
>>>     2. data, the argument to the update function seems to be undefined.
>>     FuncAnimation usually passes the frame number: 0, 1, 2, ... as the first
>>     parameter of the update function, when "frames" is None, or the number of
>>     frames. If - as here - the third parameter is a generator, it passes the
>>     yielded data to update.
>>      It may be used or not.
>     Ok, I understand that better now. But, you say "or *the number* of frames"
>     but the documentation reads "or *a number* of frames" --- what does this mean?
>
>     And I still do not understand how to use the first argument of the
>     function to be called for the animation. In another animation example
>     (histogram.py), the animation function is defined by:
>
>     def animate(i):
>         # simulate new data coming in
>         data = np.random.randn(1000
>         n, bins = np.histogram(data, 100)
>         top = bottom + n
>         verts[1::5,1] = top
>         verts[2::5,1] = top
>
>     This works of course; but, why is the "i" required? There is no other
>     reference to it in the entire script. If I remove it; i.e. use def
>     animate(): I get the following error:
>
>     TypeError: animate() takes no arguments (1 given)
>
>     I do not understand how this explains the fact that the function no longer
>     has any arguments. Please explain the meaning of this error message?
>>
>>     Please, in such cases test your programs by adding some simple tracing
>>     contraptions, say, print(data) inside update.
>     I did this and more before posting my email. I would not have posted this
>     unless I thought it was necessary. And I thought one purpose of this user
>     group was to help people --- even if they ask a question which may be
>     annoying or "stupid" in some subscribers opinion. I try to remember what a
>     very wise teacher once said --- "there is no such thing as a stupid question".
>     ------------------------------------------------------------------------------
>     BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
>     Develop your own process in accordance with the BPMN 2 standard
>     Learn Process modeling best practices with Bonita BPM through live exercises
>     http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_
>     source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF_______________________________________________
>     Matplotlib-users mailing list
>     Mat...@li...
>     <mailto:Mat...@li...>
>     https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

On 23-Apr-2015 18:48, Benjamin Root wrote:
> ... keeping conversation on-list ...
>
> The reason why you get that error is because you took out the argument from 
> the call signature. But, FuncAnimation assumes that it can send in at least 
> one argument. That argument is not optional, even if you aren't using it. So, 
> animate() was called with an argument by FuncAnimation internally, but since 
> animate() as defined by you did not have that argument, it fails.
Ok --- thanks again for the clarification. Who knows, with a little help from 
this list, I might someday be able to create some useful animations with 
Matplotlib ;-)
>
> Cheers!
> Ben Root
>
>
> On Thu, Apr 23, 2015 at 12:32 PM, Virgil Stokes <vs...@it... 
> <mailto:vs...@it...>> wrote:
>
>     On 23-Apr-2015 18:25, Benjamin Root wrote:
>>     The documentation should say "the number", not "a number". This
>>     particular argument expects either a generator, an iterable, or an
>>     integer. If none is given, it will try and figure out something for
>>     itself. The integer is used to create a number generator, and so you
>>     effectively have an iterable that supplies the first argument to the
>>     animation function.
>     Ok Benjamin :-) --- thanks for the clarification.
>>
>>     Often times, the first argument to this function is just a frame index.
>>     It is quite possible that you don't need it at all, but it is a part of
>>     the defined API that the FuncAnimation assumes to be able to call the
>>     user-supplied function.
>>
>>     Does that help?
>     Yes, this does indeed help. But I am still puzzled by the error message
>     given when I remove the argument to the animate function.
>>
>>     Ben Root
>>
>>     <shameless_plug>
>>     P.S. - My new book "Interactive Applications using Matplotlib" has an
>>     entire chapter devoted to animations
>>     </shameless_plug>
>
Thanks for this also Ben --- I will quite likely get this book. However, 
considering the complexity of Matplotlib --- only 174 pages bothers me a little. 
:-)
>
>>
>>
>>     On Thu, Apr 23, 2015 at 12:05 PM, Virgil Stokes <vs...@it...
>>     <mailto:vs...@it...>> wrote:
>>
>>         Thanks for your reply to my post, Jerzy.
>>
>>         On 23-Apr-2015 13:18, Jerzy Karczmarczuk wrote:
>>>
>>>
>>>         Le 23/04/2015 12:22, Virgil Stokes a écrit :
>>>>         The following interesting example (random_data.py) is posted at:
>>>>
>>>>         http://matplotlib.org/1.4.2/examples/animation/random_data.html
>>>>
>>>>
>>>>         import matplotlib.pyplot as plt
>>>>         import matplotlib.animation as animation
>>>         import numpy as np
>>         Yes, I forgot to include this
>>>>
>>>>         fig, ax = plt.subplots()
>>>>         line, = ax.plot(np.random.rand(10))
>>>>         ax.set_ylim(0, 1)
>>>>
>>>>         def update(data):
>>>>             line.set_ydata(data)
>>>>             return line,
>>>>
>>>>         def data_gen():
>>>>             while True: yield np.random.rand(10)
>>>>
>>>>         ani = animation.FuncAnimation(fig, update, data_gen, interval=100)
>>>>         plt.show()
>>>>
>>>>         This codes works; but, I am very confused by it. For example:
>>>>
>>>>         1. There are 3 positional arguments given for
>>>>         animation.FuncAnimation; but, in the
>>>>         API documentation for this class
>>>>         (http://matplotlib.org/api/animation_api.html), only
>>>>         two positional arguments are shown.
>>>         The third one is the third one,
>>>         "/frames/ can be a generator, an iterable, or a number of frames."
>>         This makes very little sense to me --- what does "or a number of
>>         frames" mean?
>>>         The name "data_gen" could suggest its meaning (after having read the
>>>         doc). 
>>         I am not sure what you are referencing as "the doc"; but I did read
>>         the documentation several times and English is my native language.
>>>         Note please that the keyword parameters are specified extra.
>>         I am aware of this.  Perhaps, I am a Python dummy --- when I see
>>         something like value = None in a Python API argument, I interpret
>>         this as a keyword argument and not a generator.
>>>
>>>>         2. data, the argument to the update function seems to be undefined.
>>>         FuncAnimation usually passes the frame number: 0, 1, 2, ... as the
>>>         first parameter of the update function, when "frames" is None, or
>>>         the number of frames. If - as here - the third parameter is a
>>>         generator, it passes the yielded data to update.
>>>          It may be used or not.
>>         Ok, I understand that better now. But, you say "or *the number* of
>>         frames" but the documentation reads "or *a number* of frames" ---
>>         what does this mean?
>>
>>         And I still do not understand how to use the first argument of the
>>         function to be called for the animation. In another animation example
>>         (histogram.py), the animation function is defined by:
>>
>>         def animate(i):
>>             # simulate new data coming in
>>             data = np.random.randn(1000
>>             n, bins = np.histogram(data, 100)
>>             top = bottom + n
>>             verts[1::5,1] = top
>>             verts[2::5,1] = top
>>
>>         This works of course; but, why is the "i" required? There is no other
>>         reference to it in the entire script. If I remove it; i.e. use def
>>         animate(): I get the following error:
>>
>>         TypeError: animate() takes no arguments (1 given)
>>
>>         I do not understand how this explains the fact that the function no
>>         longer has any arguments. Please explain the meaning of this error
>>         message?
>>>
>>>         Please, in such cases test your programs by adding some simple
>>>         tracing contraptions, say, print(data) inside update.
>>         I did this and more before posting my email. I would not have posted
>>         this unless I thought it was necessary. And I thought one purpose of
>>         this user group was to help people --- even if they ask a question
>>         which may be annoying or "stupid" in some subscribers opinion. I try
>>         to remember what a very wise teacher once said --- "there is no such
>>         thing as a stupid question".
>>
>>         ------------------------------------------------------------------------------
>>         BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
>>         Develop your own process in accordance with the BPMN 2 standard
>>         Learn Process modeling best practices with Bonita BPM through live
>>         exercises
>>         http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual-
>>         event?utm_
>>         source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF
>>         _______________________________________________
>>         Matplotlib-users mailing list
>>         Mat...@li...
>>         <mailto:Mat...@li...>
>>         https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>
>>
>
>

Brendan, good catch, I didn't notice Virgil's confusion earlier. I think
that is a good explanation. I remember getting very confused by all of that
stuff back when I started in Python. I think mostly because I don't know of
any other language that does argument handling like how Python does it. I
learned it all by "school-of-hard-knocks". Does anybody recommend a really
good online reference that explains the ins-and-outs of positional and
keyword arguments for newbies?

Cheers!
Ben Root


On Thu, Apr 23, 2015 at 1:00 PM, Brendan Barnwell <bre...@br...>
wrote:

> On 2015-04-23 03:22, Virgil Stokes wrote:
> >
> > 1. There are 3 positional arguments given for animation.FuncAnimation;
> > but, in the
> > API documentation for this class
> > (http://matplotlib.org/api/animation_api.html), only
> > two positional arguments are shown.
>
>         One thing I think may be misleading you is that you seem to be
> misunderstanding how positional and keyword arguments work in Python.
> Specifying a default value for an argument in a function definition
> doesn't mean that you can *only* pass it by keyword when you call it.
> Any named argument can always be passed positionally or by keyword (in
> Python 2).  For instance, if I define a function like this:
>
> def foo(a, b=2):
>      print a+b
>
> I can still call it like this:
>
> foo(8, 10)
>
> I can even call it like this (passing both arguments as keywords "out of
> order")
>
> foo(b=10, a=8)
>
>         Writing "b=2" in the function definition doesn't so much "make b a
> keyword argument" as just "specify a default value for b".  So in the
> FuncAnimation documentation you mentioned, "frames" is not required to
> be a keyword argument, and can still be passed positionally.  (In Python
> 3 there are keyword-only arguments, and even in Python 2 the variadic
> **kwargs syntax collects only keyword arguments, but those aren't
> involved as far as the "frame" argument here is concerned.)
>
> --
> Brendan Barnwell
> "Do not follow where the path may lead.  Go, instead, where there is no
> path, and leave a trail."
>     --author unknown
>
>
> ------------------------------------------------------------------------------
> BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
> Develop your own process in accordance with the BPMN 2 standard
> Learn Process modeling best practices with Bonita BPM through live
> exercises
> http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual-
> event?utm_
> source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

On 2015-04-23 03:22, Virgil Stokes wrote:
>
> 1. There are 3 positional arguments given for animation.FuncAnimation;
> but, in the
> API documentation for this class
> (http://matplotlib.org/api/animation_api.html), only
> two positional arguments are shown.

	One thing I think may be misleading you is that you seem to be 
misunderstanding how positional and keyword arguments work in Python. 
Specifying a default value for an argument in a function definition 
doesn't mean that you can *only* pass it by keyword when you call it. 
Any named argument can always be passed positionally or by keyword (in 
Python 2).  For instance, if I define a function like this:

def foo(a, b=2):
     print a+b

I can still call it like this:

foo(8, 10)

I can even call it like this (passing both arguments as keywords "out of 
order")

foo(b=10, a=8)

	Writing "b=2" in the function definition doesn't so much "make b a 
keyword argument" as just "specify a default value for b".  So in the 
FuncAnimation documentation you mentioned, "frames" is not required to 
be a keyword argument, and can still be passed positionally.  (In Python 
3 there are keyword-only arguments, and even in Python 2 the variadic 
**kwargs syntax collects only keyword arguments, but those aren't 
involved as far as the "frame" argument here is concerned.)

-- 
Brendan Barnwell
"Do not follow where the path may lead.  Go, instead, where there is no 
path, and leave a trail."
    --author unknown

... keeping conversation on-list ...

The reason why you get that error is because you took out the argument from
the call signature. But, FuncAnimation assumes that it can send in at least
one argument. That argument is not optional, even if you aren't using it.
So, animate() was called with an argument by FuncAnimation internally, but
since animate() as defined by you did not have that argument, it fails.

Cheers!
Ben Root


On Thu, Apr 23, 2015 at 12:32 PM, Virgil Stokes <vs...@it...> wrote:

>  On 23-Apr-2015 18:25, Benjamin Root wrote:
>
>   The documentation should say "the number", not "a number". This
> particular argument expects either a generator, an iterable, or an integer.
> If none is given, it will try and figure out something for itself. The
> integer is used to create a number generator, and so you effectively have
> an iterable that supplies the first argument to the animation function.
>
> Ok Benjamin :-)   --- thanks for the clarification.
>
>
>  Often times, the first argument to this function is just a frame index.
> It is quite possible that you don't need it at all, but it is a part of the
> defined API that the FuncAnimation assumes to be able to call the
> user-supplied function.
>
>  Does that help?
>
> Yes, this does indeed help. But I am still puzzled by the error message
> given when I remove the argument to the animate function.
>
>
>  Ben Root
>
>  <shameless_plug>
>  P.S. - My new book "Interactive Applications using Matplotlib" has an
> entire chapter devoted to animations
>  </shameless_plug>
>
>
> On Thu, Apr 23, 2015 at 12:05 PM, Virgil Stokes <vs...@it...> wrote:
>
>>  Thanks for your reply to my post, Jerzy.
>>
>> On 23-Apr-2015 13:18, Jerzy Karczmarczuk wrote:
>>
>>
>>
>> Le 23/04/2015 12:22, Virgil Stokes a écrit :
>>
>> The following interesting example (random_data.py) is posted at:
>>
>> http://matplotlib.org/1.4.2/examples/animation/random_data.html
>>
>>
>> import matplotlib.pyplot as plt
>> import matplotlib.animation as animation
>>
>> import numpy as np
>>
>>  Yes, I forgot to include this
>>
>>
>> fig, ax = plt.subplots()
>> line, = ax.plot(np.random.rand(10))
>> ax.set_ylim(0, 1)
>>
>> def update(data):
>>     line.set_ydata(data)
>>     return line,
>>
>> def data_gen():
>>     while True: yield np.random.rand(10)
>>
>> ani = animation.FuncAnimation(fig, update, data_gen, interval=100)
>> plt.show()
>>
>> This codes works; but, I am very confused by it. For example:
>>
>> 1. There are 3 positional arguments given for animation.FuncAnimation;
>> but, in the
>> API documentation for this class (
>> <http://matplotlib.org/api/animation_api.html>
>> http://matplotlib.org/api/animation_api.html), only
>> two positional arguments are shown.
>>
>> The third one is the third one,
>> "*frames* can be a generator, an iterable, or a number of frames."
>>
>>  This makes very little sense to me --- what does "or a number of frames"
>> mean?
>>
>> The name "data_gen" could suggest its meaning (after having read the
>> doc).
>>
>>  I am not sure what you are referencing as "the doc"; but I did read the
>> documentation several times and English is my native language.
>>
>> Note please that the keyword parameters are specified extra.
>>
>>  I am aware of this.  Perhaps, I am a Python dummy --- when I see
>> something like value = None in a Python API argument, I interpret this as a
>> keyword argument and not a generator.
>>
>>
>>  2. data, the argument to the update function seems to be undefined.
>>
>> FuncAnimation usually passes the frame number: 0, 1, 2, ... as the first
>> parameter of the update function, when "frames" is None, or the number of
>> frames. If - as here - the third parameter is a generator, it passes the
>> yielded data to update.
>>  It may be used or not.
>>
>>  Ok, I understand that better now. But, you say "or *the number* of
>> frames" but the documentation reads "or *a number* of frames" --- what
>> does this mean?
>>
>> And I still do not understand how to use the first argument of the
>> function to be called for the animation. In another animation example (
>> histogram.py), the animation function is defined by:
>>
>> def animate(i):
>>     # simulate new data coming in
>>     data = np.random.randn(1000
>>     n, bins = np.histogram(data, 100)
>>     top = bottom + n
>>     verts[1::5,1] = top
>>     verts[2::5,1] = top
>>
>> This works of course; but, why is the "i" required? There is no other
>> reference to it in the entire script. If I remove it; i.e. use def
>> animate(): I get the following error:
>>
>> TypeError: animate() takes no arguments (1 given)
>>
>> I do not understand how this explains the fact that the function no
>> longer has any arguments. Please explain the meaning of this error message?
>>
>>
>> Please, in such cases test your programs by adding some simple tracing
>> contraptions, say, print(data) inside update.
>>
>>  I did this and more before posting my email. I would not have posted
>> this unless I thought it was necessary. And I thought one purpose of this
>> user group was to help people --- even if they ask a question which may be
>> annoying or "stupid" in some subscribers opinion. I try to remember what a
>> very wise teacher once said --- "there is no such thing as a stupid
>> question".
>>
>>
>> ------------------------------------------------------------------------------
>> BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT
>> Develop your own process in accordance with the BPMN 2 standard
>> Learn Process modeling best practices with Bonita BPM through live
>> exercises
>> http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual-
>> event?utm_
>> source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>
>>
>
>

Can everyone please bring the level of snark/hostility down?  Programming
is frustrating, but antagonizing the mailing list does not help anyone.

It is not well documented, but the signature for `func` is assumed to be
`def function(required, *optional_positional)` see
https://github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/animation.py#L1107
for the line where it actually gets called.  The logic behind this is that
the function needs to have some input to know what to draw (so the state
about where in the sequence you are lives in the animation code, not in the
supplied user code).

For passing in the frame data you have several options.  The first is to
pass in an iterable of the data you want to be passed to the function (ex
np.arange(5), image_stack, image_generator), basically anything where `it =
iter(input); data = next(it)` 'does the right thing'.  The second is to
pass in a callable where repeated calls to `data = my_callable()` 'does the
right thing'  This would be useful if you want to reach out and hit some
external hardware for you data each time the animation updates.  The last
is to pass in a number of frames, which gets converted into
xrange(frames).  In all cases, the Animation turns what ever your input is
into an iterable which gets hit once pre frame (see
https://github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/animation.py#L1047
for the code version of this paragraph).

Tom

PS was finishing this up as Ben's email came in

On Thu, Apr 23, 2015 at 12:06 PM Virgil Stokes <vs...@it...> wrote:

>  Thanks for your reply to my post, Jerzy.
>
>
> On 23-Apr-2015 13:18, Jerzy Karczmarczuk wrote:
>
>
>
> Le 23/04/2015 12:22, Virgil Stokes a écrit :
>
> The following interesting example (random_data.py) is posted at:
>
> http://matplotlib.org/1.4.2/examples/animation/random_data.html
>
>
> import matplotlib.pyplot as plt
> import matplotlib.animation as animation
>
> import numpy as np
>
> Yes, I forgot to include this
>
>
> fig, ax = plt.subplots()
> line, = ax.plot(np.random.rand(10))
> ax.set_ylim(0, 1)
>
> def update(data):
>     line.set_ydata(data)
>     return line,
>
> def data_gen():
>     while True: yield np.random.rand(10)
>
> ani = animation.FuncAnimation(fig, update, data_gen, interval=100)
> plt.show()
>
> This codes works; but, I am very confused by it. For example:
>
> 1. There are 3 positional arguments given for animation.FuncAnimation;
> but, in the
> API documentation for this class (
> http://matplotlib.org/api/animation_api.html), only
> two positional arguments are shown.
>
> The third one is the third one,
> "*frames* can be a generator, an iterable, or a number of frames."
>
> This makes very little sense to me --- what does "or a number of frames"
> mean?
>
>  The name "data_gen" could suggest its meaning (after having read the
> doc).
>
> I am not sure what you are referencing as "the doc"; but I did read the
> documentation several times and English is my native language.
>
> Note please that the keyword parameters are specified extra.
>
> I am aware of this.  Perhaps, I am a Python dummy --- when I see something
> like value = None in a Python API argument, I interpret this as a keyword
> argument and not a generator.
>
>
>  2. data, the argument to the update function seems to be undefined.
>
> FuncAnimation usually passes the frame number: 0, 1, 2, ... as the first
> parameter of the update function, when "frames" is None, or the number of
> frames. If - as here - the third parameter is a generator, it passes the
> yielded data to update.
>  It may be used or not.
>
> Ok, I understand that better now. But, you say "or *the number* of
> frames" but the documentation reads "or *a number* of frames" --- what
> does this mean?
>
> And I still do not understand how to use the first argument of the
> function to be called for the animation. In another animation example (
> histogram.py), the animation function is defined by:
>
> def animate(i):
>     # simulate new data coming in
>     data = np.random.randn(1000
>     n, bins = np.histogram(data, 100)
>     top = bottom + n
>     verts[1::5,1] = top
>     verts[2::5,1] = top
>
> This works of course; but, why is the "i" required? There is no other
> reference to it in the entire script. If I remove it; i.e. use def
> animate(): I get the following error:
>
> TypeError: animate() takes no arguments (1 given)
>
> I do not understand how this explains the fact that the function no longer
> has any arguments. Please explain the meaning of this error message?
>
>
> Please, in such cases test your programs by adding some simple tracing
> contraptions, say, print(data) inside update.
>
> I did this and more before posting my email. I would not have posted this
> unless I thought it was necessary. And I thought one purpose of this user
> group was to help people --- even if they ask a question which may be
> annoying or "stupid" in some subscribers opinion. I try to remember what a
> very wise teacher once said --- "there is no such thing as a stupid
> question".
>
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