matplotlib-users Mailing List for matplotlib

Detailed instructions for adding a color map seem to be given in the user=
=20
manual on page 61. Did you try that?
M.

Hi John,

On Fri, Jul 01, 2005 at 01:44:23PM -0500, John Hunter wrote:
> clas is a little schizophrenic.  It restores some of the axes
> properties to their default (axes patch properties, grid state,
> autoscale state), but not others (hold state).  I suppose consistency
> would be a good thing here, but am not sure.  One might be able to
> make a case that some properties should reset, and some persist.  What
> do you think?
I would find it useful if there was a function which removes
all "ink" from the figure and changes nothing else.
I have no opinion about whether this function should be cla()
or some newly introduced one.

All the best,
Jochen
--=20
http://seehuhn.de/

Hello -

I wrote a small function that scales the axes so that the true scale (e.g.=
=20
the coordinates per inch) are the same along each axis.
This is useful when you contour spatial data where the x and y axes are in=
=20
meters, for example. It is equivalent to the 'axis equal' command in matlab=
.=20
Except that once given that command in matlab it is persistent. Here you=20
have to push the button every time you changed the figure window or zoom.

I added the function to the toolbar2 class and added a button to the=20
toolbar.
For the Tk backend this works great.
And I don't think it is back-end dependent, but then again, what do I know.

Any chance that such a button on the toolbar can be added to the official=
=20
release?
Or are there better ways to do this?

Mark

def axis_equal(self):
figwidth,figheight =3D self.canvas.figure.get_size_inches()
figwidth =3D 0.8*figwidth; figheight =3D 0.8*figheight
ax =3D self.canvas.figure.gca()
x1,x2 =3D ax.get_xlim()
y1,y2 =3D ax.get_ylim()
plotheight =3D y2-y1
plotwidth =3D x2-x1
if plotheight/plotwidth > figheight/figwidth: # Plot is higher than figure
wfrac =3D figheight/figwidth * plotwidth/plotheight
hfrac =3D 1.0
else:
hfrac =3D figwidth/figheight * plotheight/plotwidth
wfrac =3D 1.0
self.canvas.figure.subplots_adjust( left =3D 0.1, right =3D 0.1+wfrac*0.8,=
=20
bottom =3D 0.1, top =3D 0.1+hfrac*0.8 )
draw_if_interactive()

i would like to add colorbrewer colormaps to matplotlib,
at least for my personal use, but i would like to do this
properly so that this can be used by others.

ColorBrewer:
http://www.personal.psu.edu/faculty/c/a/cab38/ColorBrewerBeta2.html

any hints on where to start? start with the cm.py module?
extend cm.py or create a stand-alone one?

the ColorBrewer palettes could be addressed by something
like one of the following, i guess?:

   cmap=cm.colorbrewer.PuBuGn
   cmap=colorbrewer.PuBuGn

the colorbrewer palettes are specified by 3 to 9 rgb colors,
each interpolated differently, how many of these points would
be preferred in a matplotlib module?

...or even all of them, assuming 5seq as a default
(when using the above):

   cmap=cm.colorbrewer.PuBuGn.3seq
   cmap=cm.colorbrewer.PuBuGn.9seq

>>>>> "Jochen" == Jochen Voss <vo...@se...> writes:

    Jochen> Is this expected behaviour or a bug?

clas is a little schizophrenic.  It restores some of the axes
properties to their default (axes patch properties, grid state,
autoscale state), but not others (hold state).  I suppose consistency
would be a good thing here, but am not sure.  One might be able to
make a case that some properties should reset, and some persist.  What
do you think?

JDH

Hello John,

On Mon, Jun 13, 2005 at 12:29:47PM -0500, John Hunter wrote:
> So you can do, eg,=20
>=20
>    subplot(111, autoscale_on=3DFalse)

I notice that this gets turned off by cla():
the script

    from pylab import *

    figure()
    subplot(111, autoscale_on=3DFalse, xlim=3D(-1.5,1.5), ylim =3D(-1.5,1.5=
))
    ax=3Dgca()
    print ax.get_autoscale_on()

    cla()
    ax=3Dgca()
    print ax.get_autoscale_on()

prints

    False
    True

Is this expected behaviour or a bug?

All the best,
Jochen
--=20
http://seehuhn.de/

On Friday 01 July 2005 01:12 pm, Jeff Peery wrote:
> Hello I attached the matplotlibrc file. also a brief script.  Do I need
> to turn off interactive mode even though I'm using WXAgg as a backend?

No, that suggestion would only apply to the pylab interface, sorry.

So I ran your script (the third to last line should read "return True"):

$ time python sample.py

real    0m2.274s
user    0m1.192s
sys     0m0.177s

I'm using MPL 0.82, gentoo linux 2.6.12, python 2.4.1, and wx 2.6.0.0. What 
kind of speeds do you get? If you are using windows, try using this App:

class App(wx.App):
    
    def OnInit(self):
	import time
	d=time.clock()
        'Create the main window and insert the custom frame'
        frame = CanvasFrame()
        frame.Show(True)
	print time.clock()-d
        return True

-- 

Darren

>>>>> "Jeff" == Jeff Peery <jef...@se...> writes:

    Jeff> Hello, my program crashes when I try to plot using these
    Jeff> commands. Am I using the marker commands incorrectly?  I see
    Jeff> that there isn't a distinction between plotting a line and
    Jeff> symbols other than the line style (i.e., '-' or 'o').  what
    Jeff> then are markers? Thanks.

Could you provide more information, such as the exception traceback?
Can you provide a standalone script that exposes the problem?

As for lines and markers, a give line can support either or both, and
this is controlled by the linestyle and marker properties.  

JDH

Eric Emsellem wrote:
> Hi,
> a short report on 2 minor problems I face with matplotlib:
> 
> - I tried to save a figure in gif. It gave me back an error message 
> saying that basically this is not supported. This is fine of course. 
> However, then the plot window crashed, and then the whole Ipython 
> session. It would be useful then to have this error not affecting the 
> session in this way if possible.

I can see the problem in the GTK backend, but all other backends I tried under 
linux (TkAgg, QtAgg and WXAgg) all behave correctly.  This seems like a bug in 
the GTK backend to me: it puts out to the screen an error message box, but the 
OK button in that box is unresponsive.  Eventually the window manager just 
kills the window, which brings the whole python process down with it.

I don't know the backends enough to know what the right solution should be here.


Cheers,

f

Hello I attached the matplotlibrc file. also a brief script.  Do I need
to turn off interactive mode even though I'm using WXAgg as a backend?











Message: 1
From: "Jeff Peery" <jef...@se...>
To: <mat...@li...>
Date: Thu, 30 Jun 2005 08:15:54 -0700
Organization: SeaMetrics
Subject: [Matplotlib-users] slow plotting speed?

Hello, 

I wrote a small WXAgg program with wxpython. I'm plotting simple
datasets, right now I'm plotting an array of approx. 450 points. The
graphing is very slow. What can I do to speed this up? I have python
2.4, wxpython 2.4, and this is what I'm using for matplotlib
'matplotlib-0.80.win32-py2.4.exe'.


Thanks.
Jeff



--__--__--

Message: 2
From: Darren Dale <dd...@co...>
Reply-To: dd...@co...
Organization: Cornell University
To: mat...@li...
Subject: Re: [Matplotlib-users] slow plotting speed?
Date: Thu, 30 Jun 2005 11:37:26 -0400

On Thursday 30 June 2005 11:15 am, Jeff Peery wrote:
> Hello,
>
> I wrote a small WXAgg program with wxpython. I'm plotting simple 
> datasets, right now I'm plotting an array of approx. 450 points. The 
> graphing is very slow. What can I do to speed this up? I have python 
> 2.4, wxpython 2.4, and this is what I'm using for matplotlib 
> 'matplotlib-0.80.win32-py2.4.exe'.

Have you checked the list archives? There has been some discussion about
speed 
traps that you can take steps to avoid. For example, are you running a
script 
with interactive mode on? That can cause a big performance hit. 

Also, if you provide a brief example script, along with any relevant
changes 
you have made to matplotlibrc, and some detail about how long it takes
to 
plot (maybe some profiling?), we might be able to provide some more
useful 
suggestions.

-- 

Darren


--__--__--

Message: 3
To: dd...@co...
Cc: mat...@li...
Subject: Re: [Matplotlib-users] slow plotting speed?
From: John Hunter <jdh...@ac...>
Date: Thu, 30 Jun 2005 11:55:54 -0500

>>>>> "Darren" =3D=3D Darren Dale <dd...@co...> writes:


    Darren> Also, if you provide a brief example script, along with
    Darren> any relevant changes you have made to matplotlibrc, and
    Darren> some detail about how long it takes to plot (maybe some
    Darren> profiling?), we might be able to provide some more useful
    Darren> suggestions.

A script is by far the most useful thing you can provide. =20

Note that there was an optimization for line marker drawing on win32
introduced in matplotlib-0.81 From the release notes:

   Fast markers on win32 The marker cache optimization is finally
   available for win32, after an agg bug was found and fixed (thanks
   Maxim!). Line marker plots should be considerably faster now on
   win32. The original optimization announcement is ay
 
http://matplotlib.sourceforge.net/whats_new.html#0.72-line_marker_opti=
mizations_in_agg


See also http://matplotlib.sourceforge.net/faq.html#SLOW

JDH

===== Original message from Alan G. Isaac | Fri, 1 Jul 2005:
> This seems possibly related to sparkplots:

not really, but sparklines should probably also be scaled so
that the steepest slope is 45 degrees for accurate visual
decoding of the graph. [Edward Tufte has also written about
banking to 45 degrees in his excellent books.}

there is also another interesting sparkline implementation
in Python, using PIL: http://bitworking.org/projects/sparklines/


thanks for the input.

Hello, my program crashes when I try to plot using these commands. Am I
using the marker commands incorrectly?  I see that there isn't a
distinction between plotting a line and symbols other than the line
style (i.e., '-' or 'o').  what then are markers? Thanks.

Jeff         


		    if myAxes.tickFormat == 'Multiples':
                    #plot the symbols
                    axes.plot(array,
                              markersize      =mySize,
                              marker          =myShape,
                              markerfacecolor =myFaceColor,
                              markeredgecolor =myEdgeColor,
                              markeredgewidth =myWidth,
                              label           =lineLabel)

                else:
                    #plot the symbols
                    axes.plot_date(dates,
                                   array,
                                   markersize      =mySize,
                                   marker          =myShape,
                                   markerfacecolor =myFaceColor,
                                   markeredgecolor =myEdgeColor,
                                   markeredgewidth =myWidth,
                                   label           =lineLabel)

On Fri, 01 Jul 2005, Vidar Gundersen apparently wrote: 
> in Cleveland, William S. Visualizing Data (1993), 
> there is a technique called "banking to 45 degrees", 
> which calculates the aspect ratio of a plot for a more 
> accurate visual decoding of the slopes in a graph. 
> an example can be seen at the bottom of this web page: 
> http://cm.bell-labs.com/cm/ms/departments/sia/project/trellis/display.examples.html 

> the lattice package for R/S-plus has a function for this, 
> there is also an implementation in `Data visualization 
> toolbox for Matlab' http://www.datatool.com/prod01.htm 

This seems possibly related to sparkplots:
http://agiletesting.blogspot.com/2005/04/sparkplot-creating-sparklines-with.html

fwiw,
Alan Isaac

Hi again,

regarding the problem of "perturbed plot" I mentioned, I found out some 
systematic behaviour:

- I plot something
- I save it into a jpg
- I get the cursor into the window and there it gets nuts...

scatter([0,1],[0,1])
savefig('toto.jpg')

==> then put the cursor in the plot window....

and this is systematic (so this does not seem linked to a change in the 
desktop finally)

Eric

-- 
===============================================================
Observatoire de Lyon                 ems...@ob...
9 av. Charles-Andre                      tel: +33 4 78 86 83 84
69561 Saint-Genis Laval Cedex            fax: +33 4 78 86 83 86
France               http://www-obs.univ-lyon1.fr/eric.emsellem
===============================================================

Hi,
a short report on 2 minor problems I face with matplotlib:

- I tried to save a figure in gif. It gave me back an error message 
saying that basically this is not supported. This is fine of course. 
However, then the plot window crashed, and then the whole Ipython 
session. It would be useful then to have this error not affecting the 
session in this way if possible.

- I also noticed recently that when I had a plot made with matplotlib, 
and changing desktop (I am running under Linux and KDE), when I come 
back to the panel where my matplotlib session is, the plot is often (but 
not every time) "perturbed": the figure is zoomed in some corner, or 
offseted. I am not sure why this occurs, and this could be something 
specific to my setting, but just to report the problem, if this is a 
more general item (I have no clue what triggers this since it does not 
occur systematically, which I understand does not ease the debugging...:-)

Cheers
Eric
(and thanks for all this hard work. to repeat myself once more, 
matplotlib is just amazing!)

-- 
===============================================================
Observatoire de Lyon                 ems...@ob...
9 av. Charles-Andre                      tel: +33 4 78 86 83 84
69561 Saint-Genis Laval Cedex            fax: +33 4 78 86 83 86
France               http://www-obs.univ-lyon1.fr/eric.emsellem
===============================================================

are there a function for calculating "banking to 45 degrees"
and change the aspect ratio accordingly in matplotlib?

an idea:
    plot(x, aspect="bank45")
    plot(x, aspect="golden")  # golden rectangle
    plot(x, aspect=1)
    plot(x, aspect=4/3)


in Cleveland, William S. Visualizing Data (1993),
there is a technique called "banking to 45 degrees",
which calculates the aspect ratio of a plot for a more
accurate visual decoding of the slopes in a graph.
an example can be seen at the bottom of this web page:
http://cm.bell-labs.com/cm/ms/departments/sia/project/trellis/display.examples.html

the lattice package for R/S-plus has a function for this,
there is also an implementation in `Data visualization
toolbox for Matlab' http://www.datatool.com/prod01.htm

Hi all,
  I have been following this list for some time, as well as using and
spreading the news about matplotlib for all people I know and use
python. :-)

  I would like also to thank all the developers for all the amazing work 
that has been done on matplotlib, it helps me a lot in my work.

  Now the reason why I am writing to this list is to ask what is the
preferred policy for packaging matplotlib as an rpm for FC4. Yesterday was
accepted in Fedora Extras and so it should take a few days to be available.

  The packager choose to package matplotlib (called python-matplotlib) with
both dateutils and pytz packaged together while I use to package it as 3
separate packages.

  What is the opinion of the packager/developers here? Which scheme do you
prefer?

        Thanks again for this nice package.
-- 
José Abílio

Oops - sorry about the subject line :-(
Gary

>>>>> "James" == James Boyle <bo...@ll...> writes:

    James> I have also modified the colorbar code( in figure.py) to
    James> scale the width of the colorbar. I generate plots with
    James> aspect ratios of x axis long with respect to the y axis and
    James> in this situation the colorbar gets to be too fat.

The current implementation supports providing a custom axes for the
colorbar axes.  Do you think it would be useful in addition to support
something like a fracw (fraction width) keyword arg for the default
width of the colorbar when making an automatic colorbar axes.  If so
we should support this for vertical colorbars as well.  Something like
fracax=0.1, the fraction of the axis (x for horizontal or y for
vertical colorbars) taken up by the colorbar when automatically
resizing the image axes.

    James> The purpose of this long winded message is to advocate that
    James> the color bar code be modified to make this facility an
    James> option( ie specified color map, normalization, width
    James> scaling and end caps).

    James> I am willing to do this myself - but I would need some
    James> help. Previously, John suggested that I make the routine
    James> that does the fill calls derive from ScalarMappable. This
    James> would make the colorbar color map and scaling come along
    James> naturally. My skill level is such that I have not been able
    James> to get this to work - I am willing but not very able. My
    James> thought now is to make some substantial additions to
    James> colorbar.

All of this sounds fine to me -- let me know how I can help.

JDH

  

I'm getting a traceback when trying to run tex_demo.py under Windows 
(both Win98 and Win2k).
I *think* I've met the specified requirements.
Any help would be appreciated,
thanks,
Gary R.

Here's a dump with debug-annoying set:


loaded rc file C:\PYTHON23\share\matplotlib\.matplotlibrc
matplotlib version 0.82
verbose.level debug-annoying
interactive is False
platform is win32
loaded modules: ['__future__', 'copy_reg', 'sre_compile', 'distutils', 
'locale', '_sre', '__main__', 'site', '__builtin__', 'datetime', 
'encodings', 'os.path', 'encodings.encodings', 'sre_constants', 
'distutils.string', 'dateutil', 'matplotlib.datetime', 'strop', 
'matplotlib.warnings', 'encodings.codecs', 'matplotlib.sys', 're', 
'ntpath', 'pytz.sys', 'UserDict', 'distutils.sysconfig', 
'encodings.exceptions', 'nt', 'pytz.sets', 'stat', 'zipimport', 
'string', 'warnings', 'encodings.types', '_codecs', 'distutils.os', 
'matplotlib', 'encodings.cp1252', 'sys', 'pytz.tzinfo', 'pytz', 
'pytz.datetime', 'matplotlib.__future__', 'codecs', 'distutils.re', 
'matplotlib.pytz', 'types', 'matplotlib.dateutil', '_locale', 
'matplotlib.os', 'sre', 'bisect', 'matplotlib.distutils', 'signal', 
'distutils.errors', 'linecache', 'itertools', 'sets', 'exceptions', 
'sre_parse', 'pytz.bisect', 'distutils.sys', 'os']
numerix Numeric 23.7
font search path ['C:\\PYTHON23\\share\\matplotlib']
trying fontname C:\PYTHON23\share\matplotlib\cmex10.ttf
trying fontname C:\PYTHON23\share\matplotlib\cmmi10.ttf
trying fontname C:\PYTHON23\share\matplotlib\cmr10.ttf
trying fontname C:\PYTHON23\share\matplotlib\VeraMono.ttf
trying fontname C:\PYTHON23\share\matplotlib\cmsy10.ttf
trying fontname C:\PYTHON23\share\matplotlib\VeraMoBI.ttf
trying fontname C:\PYTHON23\share\matplotlib\cmtt10.ttf
trying fontname C:\PYTHON23\share\matplotlib\Vera.ttf
matplotlib data path C:\PYTHON23\share\matplotlib
loaded ttfcache file C:\PYTHON23\share\matplotlib\.ttffont.cache
backend TkAgg version 8.4
FigureCanvasAgg.draw
RendererAgg.__init__
This is e-TeX, Version 3.141592-2.2 (MiKTeX 2.4)
entering extended mode
! Undefined control sequence.
<*> 'C:\PYTHON
 
23\share\matplotlib\.tex.cache\30565a8911a6bb487e3745c0ea3c822...

! Undefined control sequence.
<*> 'C:\PYTHON23\share
 
\matplotlib\.tex.cache\30565a8911a6bb487e3745c0ea3c822...

! Undefined control sequence.
<*> 'C:\PYTHON23\share\matplotlib
 
\.tex.cache\30565a8911a6bb487e3745c0ea3c822...

! I can't find file `'C:23.tex'.
<to be read again>
                    \global
<*> 'C:\PYTHON23\share\matplotlib\.
 
tex.cache\30565a8911a6bb487e3745c0ea3c822...
Please type another input file name
! Emergency stop.
<to be read again>
                    \global
<*> 'C:\PYTHON23\share\matplotlib\.
 
tex.cache\30565a8911a6bb487e3745c0ea3c822...

No pages of output.
Transcript written on texput.log.

Exception in Tkinter callback
Traceback (most recent call last):
   File "C:\PYTHON23\lib\lib-tk\Tkinter.py", line 1345, in __call__
     return self.func(*args)
   File 
"C:\PYTHON23\Lib\site-packages\matplotlib\backends\backend_tkagg.py", 
line 148, in resize
     self.show()
   File 
"C:\PYTHON23\Lib\site-packages\matplotlib\backends\backend_tkagg.py", 
line 151, in draw
     FigureCanvasAgg.draw(self)
   File 
"C:\PYTHON23\Lib\site-packages\matplotlib\backends\backend_agg.py", line 
369, in draw
     self.figure.draw(renderer)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\figure.py", line 498, 
in draw
     for a in self.axes: a.draw(renderer)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\axes.py", line 1361, 
in draw
     self.xaxis.draw(renderer)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\axis.py", line 544, in 
draw
     tick.draw(renderer)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\axis.py", line 147, in 
draw
     if self.label1On: self.label1.draw(renderer)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\text.py", line 847, in 
draw
     self._mytext.draw(renderer)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\text.py", line 334, in 
draw
     bbox, info = self._get_layout(renderer)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\text.py", line 179, in 
_get_layout
     w,h = renderer.get_text_width_height(
   File 
"C:\PYTHON23\Lib\site-packages\matplotlib\backends\backend_agg.py", line 
237, in get_text_width_height
     Z = self.texmanager.get_rgba(s, size, dpi, rgb)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\texmanager.py", line 
276, in get_rgba
     pngfile = self.make_png(tex, dpi, force=False)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\texmanager.py", line 
113, in make_png
     dvifile = self.make_dvi(tex)
   File "C:\PYTHON23\Lib\site-packages\matplotlib\texmanager.py", line 
105, in make_dvi
     shutil.move(dvitmp, dvifile)
   File "C:\PYTHON23\lib\shutil.py", line 170, in move
     copy2(src,dst)
   File "C:\PYTHON23\lib\shutil.py", line 82, in copy2
     copyfile(src, dst)
   File "C:\PYTHON23\lib\shutil.py", line 37, in copyfile
     fsrc = open(src, 'rb')
IOError: [Errno 2] No such file or directory: 
'30565a8911a6bb487e3745c0ea3c8224.dvi'