matplotlib-users Mailing List for matplotlib

On Jun 23, 2009, at 6:01 PM, Jeff Whitaker wrote:
>>
> Pierre:  Doing what you suggest (having Basemap.__init__   
> automatically set self.ax to the current axes) will break pickling,  
> so I can't do that.

Oh, I'm sorry for the misunderstanding: I never suggested that  
Basemap.ax should be set at creation (apart from Basemap.ax=None).  
Instead, I suggested that it would be set when a drawing method is  
called that requires access to the underlying Axes (basically, all the  
plotting methods).
That way, as soon as something is plotted, we associate the basemap  
instance with one particular Axes instance and we stick to it by  
default. We can always break the link by changing basemap.ax (that is,  
associate to another Axes instance),  but we don't have the surprise  
of using the last Axes instance by default.

Now, the more I think about it, the more I'd prefer to separate  
Basemaps from Axes. Right now, self.ax assures the connection in a way  
I find frustrating. I'd prefer getting rid of Basemap.ax and force  
'ax' to be defined all the time.

Alternatively, we could consider having  2 separate objects:  a  
Basemap that stores all the projection information but has *NO*  
plotting methods, and a MapAxes that inherits from Axes and requires a  
specific Basemap attribute at creation. The current plotting routines  
would be associated with the MapAxes object.

Pierre GM wrote:
>
> On Jun 23, 2009, at 8:27 AM, Jeff Whitaker wrote:
>>
>> Pierre:  The reason I did it that way was so that the basemap 
>> instance could be created independent of any axes instances.  For 
>> instance, you can create a basemap instance before an axes instance 
>> is created, or you read in a basemap instance from a pickle. If a 
>> axes instance is associated with a Basemap instance, you can't save 
>> it in a pickle.
>
> I understand that, I use pickled basemaps all the time. It's a great 
> feature, by the way, thanks a lot.
>
>> If I understand you correctly, you are suggesting that when the 
>> basemap instance is created, the "ax" attribute be set to plt.gca() 
>> if no axes instance is passed in through the kwarg, instead of just 
>> setting it to None.
>>  In that case, an axes instance will be created and assigned to the 
>> Basemap instance if one doesn't already exist.
>
> That's the gist of it, yes. My point is that as soon something is 
> drawn, the basemap should be linked to an Axes instance. The link 
> could be overwritten later.
>
>>  I guess I don't see any compelling reason for that, since you can 
>> always assign an axes instance to the Basemap instance later (via 
>> "map.ax = plt.gca()".
>>  I'd rather have this done explicitly by the user, than have it 
>> happen automatically, with potentially surprising results.
>
> Well, talking about surprising results, the experience I was relating 
> in the original message: I load a basemap from a pickle, plot some 
> contours on it (therefore, a new Axes is created), add a colorbar (a 
> second Axes is created) and then draw a mapscale. I expect the 
> mapscale to be drawn on the axes associated with the basemap, because 
> I'm using one of the basemap's methods to plot the mapscale. With the 
> current implementation, the scale gets drawn on the colorbar.
>
> So yes, I could explicitly link the basemap to the first Axes myself. 
> I still think my suggestion would be far less confusing, but I won't 
> lose sleep over it. In any case, I think the snippet I put in the 
> latest message could simplify the code (just drop the line setting 
> self.ax to ax)...
>
>
>
>
>
>
Pierre:  Doing what you suggest (having Basemap.__init__  automatically 
set self.ax to the current axes) will break pickling, so I can't do 
that.  I think the next best thing is just to set it manually.  I know 
the colorbar behavior is annoying, but I think it's just something you 
have to live with if you use the pylab interface.

-Jeff

-- 
Jeffrey S. Whitaker         Phone  : (303)497-6313
Meteorologist               FAX    : (303)497-6449
NOAA/OAR/PSD  R/PSD1        Email  : Jef...@no...
325 Broadway                Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web    : http://tinyurl.com/5telg

This isn't the most current version, but it is a build from the SVN
branch a while ago.

http://code.patricktmarsh.com/builds/py2.5_mpl-0.98.6svn.win32.exe

The machine I used to build this took a dive so I no longer have a
working development environment so I can't build a more current .exe
for you.  Maybe in a week or two I'll have more time, but based on my
schedule, I doubt it.

Patrick
---
Patrick Marsh
Graduate Research Assistant
School of Meteorology
University of Oklahoma
http://www.patricktmarsh.com




On Tue, Jun 23, 2009 at 11:45 AM, Ryan Wagner<rw...@vn...> wrote:
> I hate to ask this question. Is there somewhere I can download the latest
> svn release compiled for Windows? I have been completely unsuccessful in
> compiling MPL for windows and rely on the binaries, but I need to work with
> the mplot3D functionality. From what I’ve seen on Linux, it looks great! TIA
>
> -Ryan
>
>
>
> ------------------------------------------------------------------------------
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> conference!
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>
>

On Tue, Jun 23, 2009 at 12:45 PM, Ryan Wagner<rw...@vn...> wrote:
> I hate to ask this question. Is there somewhere I can download the latest
> svn release compiled for Windows? I have been completely unsuccessful in
> compiling MPL for windows and rely on the binaries, but I need to work with
> the mplot3D functionality. From what I’ve seen on Linux, it looks great! TIA
>
> -Ryan

An option to consider:  run Linux in a virtual machine on a Windows
host.  I have a similar situation (unrelated to MPL) and that's what I
do.  Works great for me.   I've tried VMware, VirtualBox, and
AndLinux.  All work, but I alternate between VirtualBox (probably
because that's the one I tried first) and AndLinux.

VirtualBox  was *very easy* to set up, and it Just Works (ymmv).

AndLinux is an intriguing option; it's not a Linux emulator (if that's
the right word).  It runs a Linux kernel as a Windows process, so it
behaves as if it were a Windows app.  Similar apparent behavior is
available in VirtualBox; I think they call it "seamless mode".
AndLinux is a little bit harder to set up than VirtualBox.  I did some
**very rough** speed checks. AndLinux seems to run numpy programs at
about 80% of native Windows speed.  VirtualBox is about 10% slower
than AndLinux.  (That was *one* test on *one* script.)  Networking
works fine in both.  I've compiled Sage, and ran a Sage notebook
webserver from both VirtualBox and AndLinux, accessing the server from
another machine.  Everything works.

-gary

I hate to ask this question. Is there somewhere I can download the latest svn release compiled for Windows? I have been completely unsuccessful in compiling MPL for windows and rely on the binaries, but I need to work with the mplot3D functionality. From what I've seen on Linux, it looks great! TIA
-Ryan

 Note: Cross-posting on IPy devel and Matplotlib-users list.

Hello,

My 8 hours sleep have helped me solve the riddle of IPython pylab entry from
a regular Python script. Although it is funky and experimental, it works
just as I have been seeking it to work for months :)

Here take a look at this piece of code:

(Again, the following lines must be modified in /IPython/Shell.py to start
with pylab each time a request is made for IPython instantiation. To me a
line can be added into ipy_user_config such as always_pylab =True )

     #user_opts = set([s.replace('-','') for s in argv[:3]])     user_opts =
set(['pylab'])


#!/usr/bin/env python

#import matplotlib.pyplot as plt
#import numpy as np
import IPython

ipy = IPython.Shell.start(user_ns=locals())

a = arange(10)           ###<-- I am in IPython -pylab at this point no need
for np.arange
plot(a)                        ###<-- or plt.plot(a)

ipy.mainloop()

Later, when I drop into the IPy shell I can go ahead and manipulate my
figure appropriately. Now whos() works also :)


Gökhan

On Wed, 10 Jun 2009 16:32:08 -0400
  Jae-Joon Lee <lee...@gm...> wrote:
> I guess I misunderstood your intention.
> As you posted the message in the mpl list, I assumed 
>that you want to
> crop out the boundary of the mpl figure, which seems to 
>be not the
> case.
> Sorry for the noise.
> 
> -JJ
> 

Hi,

I found a way to run gimp (gimp2.2) in batch mode.

gimp --batch-interpreter plug_in_script_fu_eval -i -d -b 
'(script-autocrop "/home/nwagner/test.png")' '(gimp-quit 
0)'

Now I would like to run gimp from python using subprocess, 
popen2 or os.system.

How do I call gimp with the arguments from python ?

Nils
  

Hi,

could anyone reproduce this problem and/or has a solution for it? Is
there anything wrong with my code?

Best regards

Ole

Ole Streicher <ole...@gm...> writes:
> Hi Darren,
>
> Darren Dale <dsd...@gm...> writes:
>> I am really busy with other things, and can't offer suggestions unless
>> you post a short, simple, standalone script that demonstrates the
>> problem.
>
> Sure:
> --------------------------------8<-----------------------------------------
> import random
> import sys
>
> from PyQt4 import QtGui, QtCore
> from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
> from matplotlib.figure import Figure,SubplotParams
>
> class DiagramWidget(QtGui.QWidget):
>     def __init__(self, parent):
>         QtGui.QWidget.__init__(self, parent)
>         layout = QtGui.QVBoxLayout(self)
>         self.setLayout(layout)
>         self.diagram = InnerDiagramWidget(self)
>         self.scrollbar = QtGui.QScrollBar(QtCore.Qt.Horizontal, self)
>         layout.addWidget(self.diagram)
>         layout.addWidget(self.scrollbar)
>
>     def resizeEvent(self, event):
>         print 'figure resize to',  event.size()
>         QtGui.QWidget.resizeEvent(self, event)
>
> class InnerDiagramWidget(FigureCanvas):
>     def __init__(self, parent):
>         fig = Figure()
>         self.axes = fig.add_subplot(111)
>         range = xrange(10000)
>         l = [ random.randint(-5, 5) for i in range ]
>         self.axes.plot(range, l, drawstyle='steps')
>         FigureCanvas.__init__(self, fig)
>         self.setParent(parent)
>         FigureCanvas.setSizePolicy(self,
>                                    QtGui.QSizePolicy.Expanding,
>                                    QtGui.QSizePolicy.Expanding)
>         FigureCanvas.updateGeometry(self)
>
>     def resizeEvent(self, event):
>         print 'scroll resize to',  event.size()
>         FigureCanvas.resizeEvent(self, event)
>
> a = QtGui.QApplication(sys.argv)
> w = QtGui.QMainWindow()
> w.setCentralWidget(DiagramWidget(w))
> w.show()
> a.exec_()
> --------------------------------8<-----------------------------------------
>
> To see the problem undisturbed, you may remove the "resizeEvent()"
> functions.
>
> Best regards
>
> Ole

Hi Gang,

Matplotlib made it past the nomination stage and is one of the finalists in the 
'best project for academia' category. Don't forget to register your vote!

http://sourceforge.net/community/cca09/vote/

You can skip votes for categories you are not interested in if you like, but you 
can not revote, and can not change a vote once you submit.

Best
-Kaushik

Pierre GM wrote:
> All (and Jeff W. in particular),
>
> It's the time of the year where I have to draw maps in batch. I wrote  
> a script to process some data recorded at various stations,  
> interpolate the data on a grid, draw the corresponding contours on a  
> basemap, add a colorbar, and end with adding some extra information on  
> the map (scale, stations positions...).
>
> Nothing too fancy, but I ran into a problem with the last few steps.  
> As I do not give an explicit 'ax' parameter to any of the basemap  
> related methods (.contourf, .plot, .drawmapscale...), I have to rely  
> on the defaults: use self.ax if it is not None, gca() otherwise.  
> However, drawing a colorbar in midprocess switches the focus to the  
> colorbar, and the extra information I was talking about gets plotted  
> on the colorbar.
>
> Which brings me to the famous question: is it a bug or a feature ? Is  
> there any rational in *not* setting the 'ax' attribute to gca() when  
> sit hasn't been set yet and no 'ax' parameter has been specifically  
> given as input of a method ?
>   

Pierre:  The reason I did it that way was so that the basemap instance 
could be created independent of any axes instances.  For instance, you 
can create a basemap instance before an axes instance is created, or you 
read in a basemap instance from a pickle. If a axes instance is 
associated with a Basemap instance, you can't save it in a pickle.  If I 
understand you correctly, you are suggesting that when the basemap 
instance is created, the "ax" attribute be set to plt.gca() if no axes 
instance is passed in through the kwarg, instead of just setting it to 
None.  In that case, an axes instance will be created and assigned to 
the Basemap instance if one doesn't already exist.  I guess I don't see 
any compelling reason for that, since you can always assign an axes 
instance to the Basemap instance later (via "map.ax = plt.gca()".  I'd 
rather have this done explicitly by the user, than have it happen 
automatically, with potentially surprising results. 

-Jeff
> Thanks a lot in advance for any explanation:
> P.
>
>
> [As a workaround, I modified my local sources by adding a ._check_ax  
> method as below, and used :
> ax = ax or self._check_ax(ax)
> or
> ax = kwargs.pop('ax', None) or self._check_ax()
> depending on the context
>
>      def _check_ax(self, ax=None):
>          """
>      Returns the axis on which to draw.
>      By default, returns self.ax. If this latter is None, set it to  
> gca().
>          """
>          #
>          if ax is None:
>              if self.ax is None:
>                  try:
>                      ax = plt.gca()
>                  except:
>                      import matplotlib.pyplot as plt
>                      ax = plt.gca()
>                  self.ax = ax
>              return self.ax
>          return ax
>
> ------------------------------------------------------------------------------
> Are you an open source citizen? Join us for the Open Source Bridge conference!
> Portland, OR, June 17-19. Two days of sessions, one day of unconference: $250.
> Need another reason to go? 24-hour hacker lounge. Register today!
> http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>   

On Mon, Jun 22, 2009 at 13:33,
jmariette<Jer...@to...> wrote:
>
> Hi everybody,
> I have some probleme with Matplot/numpy !
> I'm using matplot v0.91.2 and I'm trying to get the hist function working !!

a rather old version of matplotlib (that's the name of the project):
we are at 0.98.5.3; try to upgrade and see if the situation improves.
Also, you don't specify the Numpy version (even if I think it's not
relevant here).

> I'm using the sample code of matplot:

with this same code and 0.98.5.3 I got the image attached

> With the same matplot lib but a different version of numpy I get 2 different
> number of bins !!! How is that possible ???
> using the 1.0.4 version of numpy, I get len(n) = 50 and len(bins) = 50 ...
> what sounds pretty right to me !! but using the version 1.2.1 (the last one
> I guess) I got len(n) = 50 and len(bins) = 51 What looks weird, doesn't it
> ???
>
> do you guys have an explanation ??
> Anybody faced the same problem ?

try to update matplotlib.

Writing note: your usage of several '?' and '!' could lead to upset
people, me for example. one char is enough to express the concept, no
need to repeat since it means you're screaming and "order" us to
reply, which is never the case on OSS projects users mailinglist.

Regards,
-- 
Sandro Tosi (aka morph, morpheus, matrixhasu)
My website: http://matrixhasu.altervista.org/
Me at Debian: http://wiki.debian.org/SandroTosi

HI to the list,

I'm playing with blit animations in a gtk window. Looking at MPL
examples I came up with a working example (attached) that shows a sin
wave with a play toggle button and a "scale" button that changes the
axis limits. In order to plot the first frame (before play is clicked)
and to correctly implement the scale action I've written the "refresh"
method that follows:

    def refresh(self):
        # This explicit draw is needed to draw the grid and to save a clean
        # background
        self.canvas.draw()
        self.background = self.canvas.copy_from_bbox(self.ax.bbox)

        # This draw is needed to draw the stand-still plot (first frame)
        self.line.set_animated(False)
        self.canvas.draw()
        self.line.set_animated(True)
            # NOTE: Saving the background here would save the line too so I have
            #              to call canvas.draw() two times

This (quite redundant) implementation works. However, (QUESTION 1) is
it expected that the following straightforward implementation:

    def refresh(self):
        self.line.set_animated(False)
        self.canvas.draw()
        self.line.set_animated(True)
        self.background = self.canvas.copy_from_bbox(self.ax.bbox)

saves in background also the line? So in this case I would have the
animation superimposed to the first frame? Seems like a bug...

Is there a better way to achieve the same result?

Furthermore, I want to attach the refresh method to some events in
order to refresh the plot event if play is not active. For example
zooming or panning with the matplotlib toolbar buttons makes the plot
disappear. (QUESTION 2) Is there such event I can use to have the line
plotted? Or is better to implement this changing from an animated to a
still state? In this latter case once I plot with animated=False I'm
not able anymore to save a clean background without the line (event
using the line.set_animated(True) method before copying the bg).

When we have solved this file could be a nice reference example.

Thanks,
    ~ Antonio

On Jun 22, 2009, at 2:57 PM, Jae-Joon Lee wrote:
> The easiest solution I can think of is doing some monkey patching.
>
>
> import matplotlib.pyplot as plt
> import matplotlib.transforms as transforms
> import numpy as np
> fig = plt.figure()
> ax = fig.add_subplot(111)
> x = [0.25, 0.75, 0.25, 0.75]
> y = [0.25, 0.25, 0.75, 0.75]
> r = 0.1 * np.ones(4)
> col = plt.scatter(x, y, np.pi*r**2)
>
>
> from matplotlib.collections import RegularPolyCollection
> class RegularPolyCollection2(RegularPolyCollection):
>    def get_transform(self):
>        ax = self.axes
>
>        sc_x = ax.bbox.width / ax.viewLim.width
>        sc_y = ax.bbox.height / ax.viewLim.height
>
>        return transforms.Affine2D().scale(sc_x, sc_y)
>
> col.__class__ = RegularPolyCollection2
>
> plt.axis('equal')
> plt.show()

Thanks Jae-Joon! This is exactly what I was looking for.

-Tony

All (and Jeff W. in particular),

It's the time of the year where I have to draw maps in batch. I wrote  
a script to process some data recorded at various stations,  
interpolate the data on a grid, draw the corresponding contours on a  
basemap, add a colorbar, and end with adding some extra information on  
the map (scale, stations positions...).

Nothing too fancy, but I ran into a problem with the last few steps.  
As I do not give an explicit 'ax' parameter to any of the basemap  
related methods (.contourf, .plot, .drawmapscale...), I have to rely  
on the defaults: use self.ax if it is not None, gca() otherwise.  
However, drawing a colorbar in midprocess switches the focus to the  
colorbar, and the extra information I was talking about gets plotted  
on the colorbar.

Which brings me to the famous question: is it a bug or a feature ? Is  
there any rational in *not* setting the 'ax' attribute to gca() when  
sit hasn't been set yet and no 'ax' parameter has been specifically  
given as input of a method ?

Thanks a lot in advance for any explanation:
P.


[As a workaround, I modified my local sources by adding a ._check_ax  
method as below, and used :
ax = ax or self._check_ax(ax)
or
ax = kwargs.pop('ax', None) or self._check_ax()
depending on the context

     def _check_ax(self, ax=None):
         """
     Returns the axis on which to draw.
     By default, returns self.ax. If this latter is None, set it to  
gca().
         """
         #
         if ax is None:
             if self.ax is None:
                 try:
                     ax = plt.gca()
                 except:
                     import matplotlib.pyplot as plt
                     ax = plt.gca()
                 self.ax = ax
             return self.ax
         return ax