matplotlib-users — Discussion related to using matplotlib

Re: [Matplotlib-users] fill_over behaves weird

[Philipp W. <ma...@ph...>]

> On Mon, 2004-08-09 at 15:19, John Hunter wrote:
>> Probably what Philipp is looking for is for fill_over to do some
>> linear interpolation between his data points, which I think gives the
>> least surprising results.  The attached code probably comes closer to
>> what he's looking for.
>
> John, you're quite right in your deduction.  For some reason I wasn't
> seeing exactly the behavior Philipp reported, although it was enough
> different from your result that I agree your code is closer to what is
> required.  His example code and yours give somewhat different results
> when used with the fill_over function on the matplotlib Web site.
>
> Boy, Python is fun...and I'm learning to like matplotlib a lot too.
>
> Steve
>
>
>

Good Morning and thank you for your help. With the new function code, the
filling works really great.

Thank you !


Philipp Weißmann

Re: [Matplotlib-users] fill_over behaves weird

[Stephen W. <ste...@cs...>]

On Mon, 2004-08-09 at 15:19, John Hunter wrote:
> Probably what Philipp is looking for is for fill_over to do some
> linear interpolation between his data points, which I think gives the
> least surprising results.  The attached code probably comes closer to
> what he's looking for.

John, you're quite right in your deduction.  For some reason I wasn't
seeing exactly the behavior Philipp reported, although it was enough
different from your result that I agree your code is closer to what is
required.  His example code and yours give somewhat different results
when used with the fill_over function on the matplotlib Web site.

Boy, Python is fun...and I'm learning to like matplotlib a lot too.

Steve

Re: [Matplotlib-users] image-loading module not found

[Steve C. <ste...@ya...>]

On Tue, 2004-08-10 at 00:55, John Hunter wrote:
> Also, Steve, we might be better off here catching *all* exceptions
> rather than just the gobject error.  Darren, would you test to see if
> this works
> 
> 
> # set icon used when windows are minimized
> if gtk.pygtk_version >= (2,2,0):
>     basedir = matplotlib.rcParams['datapath']
>     fname = os.path.join(basedir, 'matplotlib.svg')
>     try:   gtk.window_set_default_icon_from_file (fname)
>     except: print >>sys.stderr, 'Could not load matplotlib icon'

I've changed this code section of backend_gtk.py in cvs so it catches
all exceptions, prints a warning and continues running, rather than
aborting on unknown exceptions.

Steve

[Matplotlib-users] suggestion for tickmark labels

[Darren D. <dd...@co...>]

I was thinking about the way the labels are formatted. Some of the 
numbers I work with are large(10^10) and small (10^-10), and the 
formatting wasnt quite right. I am running the following as a test:

mport matplotlib
from matplotlib.matlab import *
from numarray import array

a=array(range(10))*1e6+1e7
b = array(range(10))*1e-5+1e-4
plot(a,b)

in ticker.py, in ScalarFormatter, what is the purpose of this routine?

        # if the value is just a fraction off an int, use the int
        if abs(x-long(x))<0.0001*d:
            if x<=10000: return '%d' % long(x + 0.5)
            else: return '%1.0e'%long(x)

If commented out, the labels are formatted appropriately as 
exponentials, otherwise, the level of precision can often not be useful. 
Also, in the exponential formatting block, might this
if d < 1e-3: fmt = '%1.3f'
read this?:
if d < 1e-2: fmt = '%1.3e'

One final suggestion, for formatting the exponential component:

m = self._zerorgx.match(s)
        if m:
            s = m.group(1)
            if m.group(2) is not None:
##                 s += m.group(2)
                s += m.group(2)[:2]+str(int(m.group(2)[2:])) ## my hack 
to make 3e003 look like 3e3. (Whats the "right way"?)
        s = s.replace('+', '')
        return s

Darren

Re: [Matplotlib-users] fill_over behaves weird

[John H. <jdh...@ac...>]

>>>>> "Stephen" == Stephen Walton <ste...@cs...> writes:

    Stephen> It looks to me, when running your code, that fill_over is
    Stephen> doing the right thing: filling everything between 0.5 and
    Stephen> your plotted line with a color.  It is just that with
    Stephen> your coarse spacing, you don't have points at every
    Stephen> multiple of pi/2.  However, this is with the current CVS
    Stephen> version, so you may have a problem with 0.60.2.

Probably what Philipp is looking for is for fill_over to do some
linear interpolation between his data points, which I think gives the
least surprising results.  The attached code probably comes closer to
what he's looking for.  It's probably a useful function to include in
the library - see if it meets your needs

from matplotlib.matlab import *

def fill_over(ax, x, y, val, color, over=True):
    """
    Plot filled x,y for all y over val

    If over = False, fill under
    """
    x = asarray(x).astype(nx.Float32)
    y = asarray(y).astype(nx.Float32)
    ybase = asarray(y)-val
    crossings = nonzero(less(ybase[:-1] * ybase[1:],0))
    
    on = not over
    indLast = 0
    for ind in crossings:        
        if not on:
	   on = not on
	   indLast = ind
	   continue
	thisX = array(x[indLast:ind+2]) 
	thisY = array(y[indLast:ind+2]) 
	#find the x point between x[0] and x[1] on the line
	#connecting them such that f(x) = 0.5
	#if len(thisX)<3: continue
	m = (thisY[1]-thisY[0])/(thisX[1]-thisX[0])
	x0 = (val-thisY[0])/m+thisX[0]

	thisX[0] = x0
	thisY[0] = val

	# now get the last point on the interpolated line
	m = (thisY[-1]-thisY[-2])/(thisX[-1]-thisX[-2])
	xend = (val-thisY[-2])/m+thisX[-2]

	thisX[-1] = xend
	thisY[-1] = val
	on = not on
	ax.fill(thisX, thisY, color)
	indLast = ind


x=arange(0.0, 20.0, 1.0)
y = sin(x)

plot(x,y, 'ro-')
fill_over(gca(), x, y, 0.5, '#0000FF', over=True)

show()

Re: [Matplotlib-users] fill_over behaves weird

[Stephen W. <ste...@cs...>]

On Mon, 2004-08-09 at 13:44, Philipp Weissmann wrote:

> when using fill_over, it does not draw exactly at one line but with a=20
> slightly aberration. This especially is horrible when using a low=20
> resolution:

It looks to me, when running your code, that fill_over is doing the
right thing:  filling everything between 0.5 and your plotted line with
a color.  It is just that with your coarse spacing, you don't have
points at every multiple of pi/2.  However, this is with the current CVS
version, so you may have a problem with 0.60.2.

Is fill_over supported in any way?  I had a problem finding it, and it
looks like it is in the category of unsupported contribted code.

By the way, Herr Weissman, setting up your sample data can be done
simply by typing

x=3Darange(0,20)
y=3Dsin(x)

without 'x=3D[]', 'y=3D[]', or the for loop.

--=20
Stephen Walton <ste...@cs...>
Dept. of Physics & Astronomy, Cal State Northridge

Re: [Matplotlib-users] image-loading module not found

[Darren D. <dd...@co...>]

>    Darren> After upgrading to Matplotlib 0.61, I am getting the
>    Darren> following error: Unable to load image-loading module:
>    Darren> C:\Program Files\Common
>    Darren> Files\GTK\2.0/lib/gtk-2.0/2.2.0/loaders/svg_loader.dll
>
>    Darren> The path is correct, the file exists, I wonder if the
>    Darren> mixed path seperators is causing trouble? I cant find the
>    Darren> location of this exception in matplotlib to look into it,
>    Darren> where should I look?
>
> I'm note getting this error. My guess is that it is coming from the
> final lines of backend_gtk.py
>
> # set icon used when windows are minimized
> if gtk.pygtk_version >= (2,2,0):
>    basedir = matplotlib.rcParams['datapath']
>    fname = os.path.join(basedir, 'matplotlib.svg')
>    try:   gtk.window_set_default_icon_from_file (fname)
>    except gobject.GError, exc: print >>sys.stderr, exc
>
> My win32 pygtk is older than 2.2.0 which may be why I am not seeing it.
> Would you mind seeing if this is indeed the problem (for starters,
> just replace the conditional with 'if 0:'.  If you get any more
> insight into the problem, be sure and let me know!
>
> Also, Steve, we might be better off here catching *all* exceptions
> rather than just the gobject error.  Darren, would you test to see if
> this works
>
>
> # set icon used when windows are minimized
> if gtk.pygtk_version >= (2,2,0):
>    basedir = matplotlib.rcParams['datapath']
>    fname = os.path.join(basedir, 'matplotlib.svg')
>    try:   gtk.window_set_default_icon_from_file (fname)
>    except: print >>sys.stderr, 'Could not load matplotlib icon'
>  
>
I tried this, and then started getting popups about dll's not being 
found. svg_loader.dll was not the problem.

The following were missing from Common Files\GTK\2.0\bin:
librsvg-2-2.dll
libart_lgpl_2-2.dll
libgsf-1-1.dll
libxml2.dll
zlib.dll

I had copies of all of these in my Gimp/bin directory, with the 
exception of zlib. At some point, months ago, I had downloaded zipfiles 
of all of these dll's, including zlib121 (not sure what I downloaded 
them for, probably the Gimp). Unzipped, zlib121 is called zlib1.dll, I 
renamed it zlib.dll and saved it with the other missing dll's in the 
GTK\2.0\bin. After resolving a dll clash (existing but incompatible 
zlib.dll in windows/system32), I think it is working.

By the way, the new toolbar is NICE. I like that Matplotlib is branding 
its windows, too, but what happened to the cardiogram? Matplotlib is too 
cool for a sin function, maybe the Strange Attractor is more 
appropriate? (Seems like something a Mac programmer would try.)

Darren

Re: [Matplotlib-users] Can't use WXAgg

[Barry D. <bl...@ad...>]

John,
Clean install worked.  Must have had some version
leftovers around.

Thanks.
Barry

--- John Hunter wrote:
> >>>>> "Barry" == Barry Drake
<>
> writes:
> 
>     Barry> This means that it gets past the
> try-except in
>     Barry> backend_wx.py, but can't find
> wxPySimpleApp.
> 
> Are you using the standard python shell or an IDE
> like pycrust?  If
> the latter, it may be overriding the sys,exit
which
> is why you aren't
> seeing it.  From your previous post, it looks
like
> your wx
> installation is in bad shape.  Until you can do
> 'from wxPython.wx
> import *' from the standard python shell, I
wouldn't
> bother with
> trying to tweak matplotlib.
> 
> I didn't see any error message like the one you
were
> getting in the
> wxpython archives - you might try the wx mailing
> list.
> 
> JDH
> 
> 
>
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[Matplotlib-users] fill_over behaves weird

[Philipp W. <ma...@ph...>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hallo matplitlib userse,

when using fill_over, it does not draw exactly at one line but with a 
slightly aberration. This especially is horrible when using a low 
resolution:
The following program draws a nice sinus-curve and fills all values 
above 0.5. But when reducing the resolution (i.e. set the variable res 
to "1") fill_over generates weird fillings.

from matplotlib.matlab import *
from matplotlib.helpers import *
res=0.1
# < 0.1 -> nice resolution
# > 1 -> weird fillings
x=[]
y=[]
x=arange(0,20,res)
for i in x:
	y.append(sin(i))
r=axes()
r.plot(x,y);
fill_over(r,x,y, 0.5, '#0000FF',over=True)
show()
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Version: GnuPG v1.2.4 (Darwin)

iD8DBQFBF+JHQz7EsHuNmkoRAg86AJkBLwXFD+ShYKh/k9p7ZnRLbJQarACghr7U
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=zPc3
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[Matplotlib-users] ANN matplotlib-0.61.0

[John H. <jdh...@ac...>]

What's new in matplotlib-0.61.0 - 

  Note win32 pygtk users - if you encounter problems or errors related
  to svg loading, see note at end of this email.

You can read these announce notes in html with hyperlinks at
http://matplotlib.sf.net/whats_new.html.

 * A new, enhanced, navigation toolbar.  Set 'toolbar : toolbar2' in
   matplotlibrc to try it out.  Tutorial on the new toolbar is at
   http://matplotlib.sf.net/tutorial.html#toolbar2.  Note that this
   toolbar behaves very differently than the classic toolbar.  To use
   it, you must click on the pan/zoom or zoom to rect and then
   interact with the axes by dragging your mouse over it.  The
   'forward', 'back' and 'home' buttons are used to navigate between
   previously defined view limits.  At some point we'll add multiple
   simultaneous axes support for the new toolbar but we're still
   mulling over the interface - if you need it you can still uses
   toolbar : classic.

 * Mathtext for PS!!!  Also, PS now embeds TrueType fonts so the same
   fonts you use in the *Agg GUIs should be displayed in PS
   output. Thanks Paul Barrett!

 * The imread function is used to load PNGs into arrays.  I'd like to
   add more image loaders and savers down the road -
   http://matplotlib.sourceforge.net/matplotlib.matlab.html#-imread

 * New event handling.  The functions mpl_connect and mpl_disconnect
   are used for backend independent event handling.  The callback
   signature is func(event).  See
   http://matplotlib.sf.net/tutorial.html#events and
   http://matplotlib.sf.net/examples/coords_demo.py.  The new events
   carry lots of useful information in them, like the coords in
   display and data units, the axes instance they were over, keys
   pressed during the event and more.

 * Many fixes to the SVG backend, including page layout, font support
   and image support.  SVG is now considered alpha.  You can save
   ps/eps/svg figures from GUI backends by providing the right
   extensions.  SVG is currently the fastest backend in my tests.

 * More memory leaks fixed - see
   http://matplotlib.sourceforge.net/faq.html#LEAKS for details.  My
   estimate is that complex figures (multiple subplots, images, etc..)
   now leak no more than 10-50 bytes per figure.  Down from several
   hundred bytes per figure in 0.60.

 * Vertical mathtext in backend_agg (ylabels now work properly!).
   mathtext with arbitrary rotations in PS.  Thanks Jim Benson and
   Paul Barrett!

 * Added some abbrev functions in matplotlib.lines, mainly for
   interactive users trying to save key strokes.  markerfacecolor is a
   lot of keys!  For lines, these abbrevs were added

        aa  : antialiased
        c   : color
        ls  : linestyle
        lw  : linewidth
        mec : markeredgecolor
        mew : markeredgewidth
        mfc : markerfacecolor
        ms  : markersize

   Thus you can type --not necessarily recommended for readability in
   scripts or apps but great for throwaway use in interactive shells
    
    # no antialiasing, thick green markeredge lines
    >>> plot(range(10), 'ro', aa=False, mew=2, mec='g')

   Analogs in matplotlib.patches

        aa  : antialiased
        lw  : linewidth
        ec  : edgecolor
        fc  : facecolor

 * You can put a .matplotlibrc file in a dir to override the one in
   your HOME dir.  If you have a project, say a book, and you want to
   make a bunch of images with the same look and feel for the book,
   you can place a custom rc file in the code dir for that book and
   this won't affect the configs you use for normal, interactive use.

 * Updated installing instructions at
   http://matplotlib.sf.net/installing.html (see also INSTALL in src
   distro).  Fixed a tk/osx install problem in setupext.py

 * New demo for wx/wxagg showing how to to make a flicker free cursor
   that follows the mouse and reports the coords in a status bar - see
   http://matplotlib.sf.net/examples/wxcursor_demo.py

 * Numerous bug fixes and minor enhancements detailed at
   http://matplotlib.sf.net/CHANGELOG

Downloads at http://sourceforge.net/projects/matplotlib


pygtk / win32 bug

  Alas, an enterprising matplotlib user found a bug in matplotlib-0.61
  on win32 with recent versions of pygtk even before the announcement.
  Sigh.  Is it just me or is testing multiple GUIs with multiple,
  incompatible versions on multiple platforms a pain?  

  Apparently this bug is only exposed on recent versions of pygtk for
  win32.  If you encounter problems, try removing or commenting out
  the last lines of site-packages\matplotlib\backends\backend_gtk.py
  which set the matplotlib minimization icon.  Eg, triple quote

"""
# set icon used when windows are minimized
if gtk.pygtk_version >= (2,2,0):
    basedir = matplotlib.rcParams['datapath']
    fname = os.path.join(basedir, 'matplotlib.svg')
    try:   gtk.window_set_default_icon_from_file (fname)
    except gobject.GError, exc: print >>sys.stderr, exc
"""

Re: [Matplotlib-users] Can't use WXAgg

[Barry D. <bl...@ad...>]

John,
I'm using a windows XP shell; so no extra stuff
running.

I did run all of the wxPython 2.5 demos before trying
my old matplotlib code.  The wxPython demos ran fine.

My "old" matplotlib code ran under matplotlib 0.54.2
with wxPython 2.4.1.2; I tested all of the backends
with success.

After upgrading to wxPython 2.5 all of my matplotlib
code is broken.  I even upgraded to the latest
matplotlib, 0.61.  Still doesn't work.

I'll try a clean reinstall next.  If that doesn't work
I'll go to the wx lists.

Thanks.
Barry

--- John Hunter wrote:
> >>>>> "Barry" == Barry Drake
<>
> writes:
> 
>     Barry> This means that it gets past the
> try-except in
>     Barry> backend_wx.py, but can't find
> wxPySimpleApp.
> 
> Are you using the standard python shell or an IDE
> like pycrust?  If
> the latter, it may be overriding the sys,exit
which
> is why you aren't
> seeing it.  From your previous post, it looks
like
> your wx
> installation is in bad shape.  Until you can do
> 'from wxPython.wx
> import *' from the standard python shell, I
wouldn't
> bother with
> trying to tweak matplotlib.
> 
> I didn't see any error message like the one you
were
> getting in the
> wxpython archives - you might try the wx mailing
> list.
> 
> JDH
> 
> 
>
-------------------------------------------------------
> This SF.Net email is sponsored by OSTG. Have you
> noticed the changes on
> Linux.com, ITManagersJournal and NewsForge in the
> past few weeks? Now,
> one more big change to announce. We are now OSTG-
> Open Source Technology
> Group. Come see the changes on the new OSTG site.
> www.ostg.com
> _______________________________________________
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> Mat...@li...
>
https://lists.sourceforge.net/lists/listinfo/matplotlib-users

Re: [Matplotlib-users] plot dense and large arrays, AGG limit?

[John H. <jdh...@ac...>]

>>>>> "Jin-chung" == Jin-chung Hsu <hs...@st...> writes:

    Jin-chung> One would expect the following will fill up the plot
    Jin-chung> window:
    >>>> n=zeros(20000) n[::2]=1 plot(n)

    Jin-chung> The plot "stops" a little more than half way, as if it
    Jin-chung> "runs out of ink".

    Jin-chung> It happens on Linux as well as Solaris, using either
    Jin-chung> numarray and Numeric, and both TkAgg and GTKAgg, but
    Jin-chung> not GTK.  Is this due to some AGG limitation?


A bit more information on this problem - I just got this post from
Maxim on the Agg mailing list

    Hi John,

    You have this wierdness because your path is too long, it exceeds
    the maximal limit of memory allowed for the scanline
    rasterizer. It's 4196*1024 cells (pixels), or 67MB. I added this
    limit in order not to crash the whole system in case if you or I
    have an infinite loop of rasterizer::line_to. I'm not sure if it's
    the best solution, but I don't see anything better. What is the
    necessity to draw such long uninterrupted paths?

    McSeem

This explains several of the "strange observations".  The problem
occured when the axes limits were [-1,1] and not [-2,2] because in the
latter case the pixel coverage was smaller.  It occured for plotting
solid lines but not for circles for the same reason.

Probably the best solution is to break long line paths into multiple
paths in the agg backend.  It should be a pretty rare event - there
aren't too many plots that try and cover that many pixels with lines,
but it does happen and should be accounted for...

JDH

Re: [Matplotlib-users] plot_date

[John H. <jdh...@ac...>]

>>>>> "Jin-chung" == Jin-chung Hsu <hs...@st...> writes:

    Jin-chung> Hi: I have encountered several problems with plot_date.
    Jin-chung> I am using 0.60.1 (maybe fixed in 0.60.2?) on Solaris.

    Jin-chung> (1) If I put a smaller number as one of the dates (as
    Jin-chung> seconds), it raises the "before the epoch" error.  But
    Jin-chung> I think plot_date should accomodate dates earlier than
    Jin-chung> 1970.


Yes, this is on the goals page - when I implemented the dates module,
I wanted to be able to support python2.2, and thus fell back on the
time module which is based on the epoch.  It's a limitation that needs
to be addressed.  On possibility is to require python2.3 for datetime
support - probably better is to use datetime and an earlier epoch
where available.

    Jin-chung> (2) After the error in (1) happens, even if I put
    Jin-chung> "legal" dates and run plot_date again, it still issues
    Jin-chung> the same error.  It seems there is some kind of switch
    Jin-chung> needs to be reset.

Does cla() help - normally all plot data is kept around until the axes
are cleared.  This happens by default is axes.hold is False in rc or
if you manually set

  >>> hold(False)

If you still have the problem after the axes are cleared, let me know
because then it's a bug.

    Jin-chung> (3) if, e.g. t=[1.e8, 1.1e8], the x-axis tick labels
    Jin-chung> are crowded.

This appears to be fixed in 0.61 with Peter Groszkowski
MultiWeekLocator submission.

Thanks,
JDH

[Matplotlib-users] plot_date

[Jin-chung H. <hs...@st...>]

Hi:

I have encountered several problems with plot_date.  I am using 0.60.1 (maybe 
fixed in 0.60.2?) on Solaris.

(1) If I put a smaller number as one of the dates (as seconds), it raises the 
"before the epoch" error.  But I think plot_date should accomodate dates earlier 
than 1970. 

>>> t=[1.e7, 1.e8]
>>> plot_date(t,y,None)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "/usr/ra/pysoft/2.3.3/matplotlib/matlab.py", line 1207, in plot_date
    try: lines =  gca().plot_date(*args, **kwargs)
  File "/usr/ra/pysoft/2.3.3/matplotlib/axes.py", line 1496, in plot_date
    ret = self.plot(e, y, fmt, **kwargs)
  File "/usr/ra/pysoft/2.3.3/matplotlib/axes.py", line 1472, in plot
    self.autoscale_view()
  File "/usr/ra/pysoft/2.3.3/matplotlib/axes.py", line 445, in autoscale_view
    tup = locator.autoscale()
  File "/usr/ra/pysoft/2.3.3/matplotlib/ticker.py", line 728, in autoscale
    dmin = self.epochConverter.floor_month(dmin)
  File "/usr/ra/pysoft/2.3.3/matplotlib/dates.py", line 354, in floor_month
    if y<1970: raise RuntimeError('You are before the epoch!')
RuntimeError: You are before the epoch!


(2) After the error in (1) happens, even if I put "legal" dates and run 
plot_date again, it still issues the same error.  It seems there is some kind of 
switch needs to be reset.

(3) if, e.g. t=[1.e8, 1.1e8], the x-axis tick labels are crowded.


JC Hsu

Re: [Matplotlib-users] Can't use WXAgg

[John H. <jdh...@ac...>]

>>>>> "Barry" == Barry Drake <bl...@ad...> writes:

    Barry> This means that it gets past the try-except in
    Barry> backend_wx.py, but can't find wxPySimpleApp.

Are you using the standard python shell or an IDE like pycrust?  If
the latter, it may be overriding the sys,exit which is why you aren't
seeing it.  From your previous post, it looks like your wx
installation is in bad shape.  Until you can do 'from wxPython.wx
import *' from the standard python shell, I wouldn't bother with
trying to tweak matplotlib.

I didn't see any error message like the one you were getting in the
wxpython archives - you might try the wx mailing list.

JDH

Re: [Matplotlib-users] Can't use WXAgg

[Barry D. <bl...@ad...>]

Update to my previous post:

When I use the command line to use WXAgg, I receive
the following traceback:
>>> import matplotlib
>>> matplotlib.use("WXAgg")
>>> from matplotlib.matlab import *
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File
"C:\Python23\Lib\site-packages\matplotlib\matlab.py",
line 144, in ?
    from backends import new_figure_manager,
error_msg, \
  File
"C:\Python23\Lib\site-packages\matplotlib\backends\__init__.py",
line 39, in ?
    from backend_wxagg import \
  File
"C:\Python23\Lib\site-packages\matplotlib\backends\backend_wxagg.py",
line 20, in ?
    from backend_wx import FigureManager
  File
"C:\Python23\Lib\site-packages\matplotlib\backends\backend_wx.py",
line 116, in ?
    wxapp = wxPySimpleApp()
NameError: name 'wxPySimpleApp' is not defined

This means that it gets past the try-except in
backend_wx.py, but can't find wxPySimpleApp.

In the previous post, when runing the code from a
file, the exception was caught and 
a sysexit() occurred.

I don't understand why in one case the exception is
caught and not in the other.
In either case, I'm still unable to use the wx
backend.

Thanks.
Barry Drake

--- Barry Drake wrote:
&gt; Having a problem with the WX backend; details
&gt; follow.
&gt; 
&gt; I have wxPython 2.5 and
&gt; matplotlib-0.60.2.win32-py2.3
&gt; installed.
&gt; 
&gt; My code snippet:
&gt; import matplotlib
&gt; matplotlib.use("WXAgg")
&gt; from matplotlib.matlab import *
&gt; 
&gt; Error msg:
&gt; Matplotlib backend_wx requires wxPython be
installed
&gt; 
&gt; Code snippet from:
&gt;
C:\Python23\Lib\site-packages\matplotlib\backends\backend_wx.py
&gt; try:
&gt;     from wxPython.wx import *
&gt; except:
&gt;     print &gt;&gt;sys.stderr, "Matplotlib
backend_wx
&gt; requires wxPython be installed"
&gt;     sys.exit()    
&gt; 
&gt; I receive the following traceback when I try to
&gt; invoke
&gt; this from the command line:
&gt; 
&gt; Enthought Edition build 1057
&gt; Python 2.3.3 (#51, Feb 16 2004, 04:07:52) [MSC
&gt; v.1200
&gt; 32 bit (Intel)] on win32
&gt; Type "help", "copyright", "credits" or "license"
for
&gt; more information.
&gt; &gt;&gt;&gt; from wxPython.wx import *
&gt; Traceback (most recent call last):
&gt;   File "&lt;stdin&gt;", line 1, in ?
&gt;   File
&gt;
"C:\Python23\lib\site-packages\wxPython\__init__.py",
&gt; line 10, in ?
&gt;     import _wx
&gt;   File
&gt; "C:\Python23\Lib\site-packages\wxPython\_wx.py",
&gt; line
&gt; 3, in ?
&gt;     from core import *
&gt;   File
&gt; "C:\Python23\Lib\site-packages\wxPython\core.py",
&gt; line
&gt; 15, in ?
&gt;     import wx.core
&gt;   File
&gt; "C:\Python23\lib\site-packages\wxPython\wx.py",
&gt; line 4, in ?
&gt;     from misc import *
&gt;   File
&gt; "C:\Python23\lib\site-packages\wxPython\misc.py",
&gt; line
&gt; 15, in ?
&gt;     import wx.misc
&gt;   File
&gt; "C:\Python23\lib\site-packages\wxPython\wx.py",
&gt; line 6, in ?
&gt;     from misc2 import *
&gt;   File
&gt;
"C:\Python23\lib\site-packages\wxPython\misc2.py",
&gt; line 4, in ?
&gt;     from windows import *
&gt;   File
&gt;
"C:\Python23\lib\site-packages\wxPython\windows.py",
&gt; line 15, in ?
&gt;     import wx.windows
&gt;   File
&gt; "C:\Python23\lib\site-packages\wxPython\wx.py",
&gt; line 10, in ?
&gt;     from gdi import *
&gt;   File
&gt; "C:\Python23\lib\site-packages\wxPython\gdi.py",
&gt; line
&gt; 15, in ?
&gt;     import wx.gdi
&gt;   File
&gt; "C:\Python23\lib\site-packages\wxPython\wx.py",
&gt; line 12, in ?
&gt;     from fonts import *
&gt;   File
&gt;
"C:\Python23\lib\site-packages\wxPython\fonts.py",
&gt; line 120, in ?
&gt;     class wxFontPtr(wxObjectPtr):
&gt; NameError: name 'wxObjectPtr' is not defined
&gt; 
&gt; code snippet from:
&gt; C:\Python23\Lib\site-packages\wxPython\fonts.py
&gt; class wxFontPtr(wxObjectPtr):
&gt; 
&gt; This doesn't seem to be a problem specific to
&gt; matplotlib.  But, I'm wondering if anyone has
&gt; already solved this or I'm just missing
something.
&gt; 
&gt; Thanks.
&gt; Barry Drake
&gt; 
&gt; 
&gt; 
&gt;
-------------------------------------------------------
&gt; This SF.Net email is sponsored by OSTG. Have you
&gt; noticed the changes on
&gt; Linux.com, ITManagersJournal and NewsForge in the
&gt; past few weeks? Now,
&gt; one more big change to announce. We are now OSTG-
&gt; Open Source Technology
&gt; Group. Come see the changes on the new OSTG site.
&gt; www.ostg.com
&gt; _______________________________________________
&gt; Matplotlib-users mailing list
&gt; Mat...@li...
&gt;
https://lists.sourceforge.net/lists/listinfo/matplotlib-users

Re: [Matplotlib-users] Horizontal bar chart?

[John H. <jdh...@ac...>]

>>>>> "Eli" == Eli Glaser <eg...@se...> writes:

    Eli> Hello, I was wondering if there is any way to do a horizontal
    Eli> bar chart using Matplotlib?  Any responses would be greatly
    Eli> appreciated.

Not currently.  Implementing matlab's 'barh' is left as an exercise to
the reader :-)

Kidding aside, this would be very easy to implement following the
example of 'bar' and would be a nice addition.  Submissions welcome!

JDH

The matlab barh doc string

>> help barh
 
 BARH Horizontal bar graph.
     BARH(X,Y) draws the columns of the M-by-N matrix Y as M groups of
     N horizontal bars.  The vector X must be monotonically increasing
     or decreasing.
  
     BARH(Y) uses the default value of X=1:M.  For vector inputs,
     BARH(X,Y) or BARH(Y) draws LENGTH(Y) bars.  The colors are set by
     the colormap.
  
     BARH(X,Y,WIDTH) or BARH(Y,WIDTH) specifies the width of the
     bars. Values of WIDTH > 1, produce overlapped bars.  The
     default value is WIDTH=0.8.
  
     BARH(...,'grouped') produces the default vertical grouped bar chart.
     BARH(...,'stacked') produces a vertical stacked bar chart.
     BARH(...,LINESPEC) uses the line color specified (one of 'rgbymckw').
  
     H = BARH(...) returns a vector of patch handles.
  
     Use SHADING FACETED to put edges on the bars.  Use SHADING FLAT to
     turn them off.
  
     Examples: subplot(3,1,1), barh(rand(10,5),'stacked'), colormap(cool)
               subplot(3,1,2), barh(0:.25:1,rand(5),1)
               subplot(3,1,3), barh(rand(2,3),.75,'grouped')
  
     See also PLOT, BAR, BAR3H.
 

[Matplotlib-users] Can't use WXAgg

[Barry D. <bl...@ad...>]

Having a problem with the WX backend; details follow.

I have wxPython 2.5 and matplotlib-0.60.2.win32-py2.3
installed.

My code snippet:
import matplotlib
matplotlib.use("WXAgg")
from matplotlib.matlab import *

Error msg:
Matplotlib backend_wx requires wxPython be installed

Code snippet from:
C:\Python23\Lib\site-packages\matplotlib\backends\backend_wx.py
try:
    from wxPython.wx import *
except:
    print >>sys.stderr, "Matplotlib backend_wx
requires wxPython be installed"
    sys.exit()    

I receive the following traceback when I try to invoke
this from the command line:

Enthought Edition build 1057
Python 2.3.3 (#51, Feb 16 2004, 04:07:52) [MSC v.1200
32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for
more information.
>>> from wxPython.wx import *
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File
"C:\Python23\lib\site-packages\wxPython\__init__.py",
line 10, in ?
    import _wx
  File
"C:\Python23\Lib\site-packages\wxPython\_wx.py", line
3, in ?
    from core import *
  File
"C:\Python23\Lib\site-packages\wxPython\core.py", line
15, in ?
    import wx.core
  File "C:\Python23\lib\site-packages\wxPython\wx.py",
line 4, in ?
    from misc import *
  File
"C:\Python23\lib\site-packages\wxPython\misc.py", line
15, in ?
    import wx.misc
  File "C:\Python23\lib\site-packages\wxPython\wx.py",
line 6, in ?
    from misc2 import *
  File
"C:\Python23\lib\site-packages\wxPython\misc2.py",
line 4, in ?
    from windows import *
  File
"C:\Python23\lib\site-packages\wxPython\windows.py",
line 15, in ?
    import wx.windows
  File "C:\Python23\lib\site-packages\wxPython\wx.py",
line 10, in ?
    from gdi import *
  File
"C:\Python23\lib\site-packages\wxPython\gdi.py", line
15, in ?
    import wx.gdi
  File "C:\Python23\lib\site-packages\wxPython\wx.py",
line 12, in ?
    from fonts import *
  File
"C:\Python23\lib\site-packages\wxPython\fonts.py",
line 120, in ?
    class wxFontPtr(wxObjectPtr):
NameError: name 'wxObjectPtr' is not defined

code snippet from:
C:\Python23\Lib\site-packages\wxPython\fonts.py
class wxFontPtr(wxObjectPtr):

This doesn't seem to be a problem specific to
matplotlib.  But, I'm wondering if anyone has
already solved this or I'm just missing something.

Thanks.
Barry Drake

Re: [Matplotlib-users] image-loading module not found

[John H. <jdh...@ac...>]

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

    Darren> After upgrading to Matplotlib 0.61, I am getting the
    Darren> following error: Unable to load image-loading module:
    Darren> C:\Program Files\Common
    Darren> Files\GTK\2.0/lib/gtk-2.0/2.2.0/loaders/svg_loader.dll

    Darren> The path is correct, the file exists, I wonder if the
    Darren> mixed path seperators is causing trouble? I cant find the
    Darren> location of this exception in matplotlib to look into it,
    Darren> where should I look?

I'm note getting this error. My guess is that it is coming from the
final lines of backend_gtk.py

# set icon used when windows are minimized
if gtk.pygtk_version >= (2,2,0):
    basedir = matplotlib.rcParams['datapath']
    fname = os.path.join(basedir, 'matplotlib.svg')
    try:   gtk.window_set_default_icon_from_file (fname)
    except gobject.GError, exc: print >>sys.stderr, exc

My win32 pygtk is older than 2.2.0 which may be why I am not seeing it.
Would you mind seeing if this is indeed the problem (for starters,
just replace the conditional with 'if 0:'.  If you get any more
insight into the problem, be sure and let me know!

Also, Steve, we might be better off here catching *all* exceptions
rather than just the gobject error.  Darren, would you test to see if
this works


# set icon used when windows are minimized
if gtk.pygtk_version >= (2,2,0):
    basedir = matplotlib.rcParams['datapath']
    fname = os.path.join(basedir, 'matplotlib.svg')
    try:   gtk.window_set_default_icon_from_file (fname)
    except: print >>sys.stderr, 'Could not load matplotlib icon'


FYI

C:\Program Files\Common Files\GTK\2.0 # looks like the default registry path

/lib/gtk-2.0/2.2.0/loaders/svg_loader.dll # looks like a path from pkgconfig

JDH

[Matplotlib-users] image-loading module not found

[Darren D. <dd...@co...>]

After upgrading to Matplotlib 0.61, I am getting the following error:

Unable to load image-loading module: C:\Program Files\Common 
Files\GTK\2.0/lib/gtk-2.0/2.2.0/loaders/svg_loader.dll

The path is correct, the file exists, I wonder if the mixed path 
seperators is causing trouble? I cant find the location of this 
exception in matplotlib to look into it, where should I look?

[Matplotlib-users] Horizontal bar chart?

[Eli G. <eg...@se...>]

Hello,

I was wondering if there is any way to do a horizontal bar chart using =
Matplotlib?  Any responses would=20
be greatly appreciated.

Thanks,

Eli

[Matplotlib-users] plot_date... yet again...

[Peter G. <pgr...@ge...>]

Hi:

Below is a little part of my post from a while ago regarding x-axis 
scaling on plot_date plots.

>
> 2) The auto-scaling in plot_date() does not scale properly in some 
> special cases. Consider this:
>
> -----------------
> from matplotlib.matlab import *
>
> time2= [
> 1087321489.89, 1087321500.0,
> 1087321789.89, 1087321800.0, 1087322089.89, 1087322100.0, 
> 1087322389.89, 1087322700.0, 1087322989.89,
> 1087323000.0, 1087323289.89, 1087323300.0, 1087323589.89, 
> 1087323600.0, 1087323889.89, 1087323900.0,
> 1087324189.89, 1087324200.0, 1087324489.89, 1087324500.0, ]
> data2=[ 3.02,
> 3.02,
> 3.14,
> 3.14,
> 3.21,
> 3.21,
> 3.26,
> 3.26,
> 3.39,
> 3.39,
> 3.51,
> 3.51,
> 3.58,
> 3.58,
> 3.75,
> 3.75,
> 4.0,
> 4.0,
> 4.22,
> 4.22,]
>
> plot_date(time2, data2, None, '-', color='b')
> xlabel('time')
> grid(True)
>
> show()
> ---------------
>
> The same thing happens over differnt ranges when the amount of ticks 
> is large. Perhaps you may use something similar to the code below
> (from axes.py) to deal with these things. Note the ceilings get rid of 
> the AssertErrors in ticks.Base when int() gives zero. Also, to 
> finalize this,
> one would have to write a DayMultiLocator type class for the Weeks, 
> otherwise when the number of weeks is close, but less then the number
> of weeks in numticks*months it will get crowded. This will probably be 
> a little more involved than dealing with days, but perhaps one could use
> your existent WeekdayLocator class to simplify the problem.


I added a quick and dirty version of this WeekMultiLocator that handles 
cases when the time range is many weeks but less than 5 months (say 17 
weeks) and the ticks get over-crowded. Ideally one could have the weeks 
always start on some particular day - say Monday, but for me it doesnt 
really matter, and with the simple code below, thing seem to come out 
quite nice.


In axes.py need:

Line ~19:

from ticker import YearLocator, MonthLocator, WeekdayLocator, \
     DayLocator, HourLocator, MinuteLocator, DateFormatter, 
DayMultiLocator, WeekMultiLocator


Line ~1475:

    def plot_date(self, d, y, converter, fmt='bo', **kwargs):
        """
        plot_date(d, y, converter, fmt='bo', **kwargs)

        d is a sequence of dates; converter is a dates.DateConverter
        instance that converts your dates to seconds since the epoch for
        plotting.  y are the y values at those dates.  fmt is a plot
        format string.  kwargs are passed on to plot.  See plot for more
        information.

        pass converter = None if your dates are already in epoch format
        """

        if not self._hold: self.cla()

        if converter is not None:
            e = array([converter.epoch(thisd) for thisd in d])
        else:
            e = d
           
        assert(len(e))
        ret = self.plot(e, y, fmt, **kwargs)

        span  = self.dataLim.intervalx().span()
        if span==0: span = SEC_PER_HOUR
        minutes = span/SEC_PER_MIN
        hours  = span/SEC_PER_HOUR
        days   = span/SEC_PER_DAY
        weeks  = span/SEC_PER_WEEK
        months = span/(SEC_PER_DAY*31)  # approx       
        years  = span/(SEC_PER_WEEK*52)   # approx

        numticks = 5
        if years>numticks:
            locator = YearLocator(math.ceil(years/numticks)) 
            fmt = '%Y'
        elif months>numticks:
            locator = MonthLocator(math.ceil(months/numticks)) 
            fmt = '%b %Y'
        elif weeks>numticks:
            locator = WeekMultiLocator(math.ceil(weeks/numticks))
            fmt = '%a, %b %d'
        elif days>numticks:
            locator = DayMultiLocator(math.ceil(days/numticks))
            fmt = '%b %d'
        elif hours>numticks:
            locator = HourLocator(math.ceil(hours/numticks))
            fmt = '%H:%M\n%b %d'
        elif minutes>numticks:
            locator = MinuteLocator(math.ceil(minutes/numticks))
            fmt = '%H:%M:%S'
        else:
            locator = MinuteLocator(1)
            fmt = '%H:%M:%S'

        formatter = DateFormatter(fmt)
        self.xaxis.set_major_locator(locator)
        self.xaxis.set_major_formatter(formatter)
        self.autoscale_view()
        return ret

In ticks.py:

Need to add:

class WeekMultiLocator(MultipleLocator):
    """
    Make ticks on day which are multiples of base
    """
    def __init__(self, base):
        MultipleLocator.__init__(self, base*SEC_PER_WEEK)



-- 
Peter Groszkowski         Gemini Observatory
Tel: +1 808 974-2509      670 N. A'ohoku Place
Fax: +1 808 935-9235      Hilo, Hawai'i 96720, USA

Re: [Matplotlib-users] bar() in matlab

[Gary R. <ga...@em...>]

>     Stephen> However, in either case, the bars' left edge is at the x
>     Stephen> coordinate rather than being centered on it.  I know this
>     Stephen> is the documented behavior, but Matlab centers the bars
>     Stephen> on the given X coordinates.  How do people feel about
>     Stephen> changing matplotlib to match the Matlab behavior?  I've
>     Stephen> changed my copy locally.
> 
> Hi Stephen,
> I'd be happy with this change.  I CCd Gary Ruben who has done a lot of
> work on the bar function because he'll likely have an opinion.

Hi John,

Since you ask, the proposed change makes perfect sense to me.
Oh, and you're definitely overstating the changes I've done on barplots which was limited to tinkering with the errorbar part.

Gary
-- 
___________________________________________________________
Sign-up for Ads Free at Mail.com
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Re: [Matplotlib-users] Color for plus symbol always black

[John H. <jdh...@ac...>]

>>>>> "Richard" == Richard Taylor <rt...@ec...> writes:

    Richard> I recently upgraded to the binary for Windows version
    Richard> 0.60.2 and found that the plus (+) symbol always plots in
    Richard> black even though a color is specified.  My fix was to
    Richard> change the parameter lines.markeredgecolor to the color I
    Richard> wanted using the rc() command and then to revert to the
    Richard> default using rcdefaults().  This works ok for me but I
    Richard> thought you might want to know in case it's a bug.

Yes, this is a bug, sort of.  '+' is a marker.  In the current
matplotlib, the colorarg only sets the marker face color but not the
edge color.  For circles and the like, this is normally not a
problem.  But for '+' it makes no sense.

In the next release, color args will affect both the edge and face
colors, and you can override this by providing a kwarg, eg

  >>> plot(range(10), 'r+')  # red plusses

  >>> plot(range(10), 'ro')  # red circles, edge and face

  >>> plot(range(10), 'ro', markeredgecolor='k')  # red face, black edge

Thanks for letting me know.

JDH

[Matplotlib-users] Color for plus symbol always black

[Richard T. <rt...@ec...>]

I recently upgraded to the binary for Windows version 0.60.2 and found that
the plus (+) symbol always plots in black even though a color is specified.
My fix was to change the parameter lines.markeredgecolor to the color I
wanted using the rc() command and then to revert to the default using
rcdefaults().  This works ok for me but I thought you might want to know in
case it's a bug.

 

Regards,

Rich