matplotlib-users Mailing List for matplotlib

Johann Cohen-Tanugi <co...@sl...> writes:

> I would like to know if there is an easy to invert a axis (specifically 
> the x-axis), id est to have the labels between say 0 an1 automatically 
> run from right to left.

setp(gca(), 'xlim', reversed(getp(gca(), 'xlim')))

i.e., just put the larger limit before the smaller one.

-- 
Jouni K. Seppänen
http://www.iki.fi/jks

hello,
I would like to know if there is an easy to invert a axis (specifically 
the x-axis), id est to have the labels between say 0 an1 automatically 
run from right to left. This is particularly welcome in astrophysical 
context, where the spherical x coordinate of a 2D image is often reversed.
thanks,
Johann

Jose,

Attached is an example that should at least point you in the right 
direction.  I will also add it to the examples directory in the 
distribution.

Eric


Jose Gomez-Dans wrote:
> Hi,
> I am using Matplotlib to produce colormaps which I use with other
> programs. I would like to produce a PNG file with the used colormap
> (so that I can overlay). Rather than doing an imshow(<something>)
> followed by colorbar, is there an easy way I could pass the colorbar
> my cmap instance to have it plotted on its own? In essence, what I
> want to do is to do a savefig, and get something along the lines of
> what is shown here: <http://www.igidl.ul.pt/colorscale.gif>. I will
> need to change the scale (i.e.,, the numbers :D) with each run.
> 
> So far, I have "cut+pasted" from a whole image, which is hardly convenient! :(
> 
> Cheers,
> Jose

Xavier Gnata <gn...@ob...> writes:

> I do not know if we should post bug reports against matplotlib svn. 

Posting bug reports is likely to be helpful, but I suspect the
developers' list might be more appropriate for bugs in the svn version.
For bugs in released versions, I think John has told people to file a
bug in the Sourceforge tracker and also send a message to the mailing
list.

> Anyway, imshow is now fully broken this way :
[...]
> --> 200             w, h, d = renderer.get_text_width_height_descent(
> ValueError: need more than 2 values to unpack

It's not in imshow really, but in the usetex branch of
get_text_width_height_descent in the agg backend. I fixed the immediate
problem, though baseline alignment is unlikely to work with usetex as of
now.

-- 
Jouni K. Seppänen
http://www.iki.fi/jks

Hi,

I do not know if we should post bug reports against matplotlib svn. 
Please tell us.
Anyway, imshow is now fully broken this way :

imshow(ones((100,100)))

/usr/lib/python2.4/site-packages/matplotlib/pylab.py in imshow(*args, 
**kwargs)
   1960     try:
   1961         ret =  gca().imshow(*args, **kwargs)
-> 1962         draw_if_interactive()
   1963     except:
   1964         hold(b)

/usr/lib/python2.4/site-packages/matplotlib/backends/backend_tkagg.py in 
draw_if_interactive()
     56         figManager =  Gcf.get_active()
     57         if figManager is not None:
---> 58             figManager.show()
     59
     60

/usr/lib/python2.4/site-packages/matplotlib/backends/backend_tkagg.py in 
show(self)
    350             if sys.platform=='win32' : self.window.update()
    351         else:
--> 352             self.canvas.draw()
    353         self._shown = True
    354

/usr/lib/python2.4/site-packages/matplotlib/backends/backend_tkagg.py in 
draw(self)
    189
    190     def draw(self):
--> 191         FigureCanvasAgg.draw(self)
    192         tkagg.blit(self._tkphoto, self.renderer._renderer, 
colormode=2)
    193         self._master.update_idletasks()

/usr/lib/python2.4/site-packages/matplotlib/backends/backend_agg.py in 
draw(self)
    381
    382         self.renderer = self.get_renderer()
--> 383         self.figure.draw(self.renderer)
    384
    385     def get_renderer(self):

/usr/lib/python2.4/site-packages/matplotlib/figure.py in draw(self, 
renderer)
    610
    611         # render the axes
--> 612         for a in self.axes: a.draw(renderer)
    613
    614         # render the figure text

/usr/lib/python2.4/site-packages/matplotlib/axes.py in draw(self, 
renderer, inframe)
   1336
   1337         for zorder, i, a in dsu:
-> 1338             a.draw(renderer)
   1339
   1340         self.transData.thaw()  # release the lazy objects

/usr/lib/python2.4/site-packages/matplotlib/axis.py in draw(self, 
renderer, *args, **kwargs)
    588             tick.set_label1(label)
    589             tick.set_label2(label)
--> 590             tick.draw(renderer)
    591             if tick.label1On and tick.label1.get_visible():
    592                 extent = tick.label1.get_window_extent(renderer)

/usr/lib/python2.4/site-packages/matplotlib/axis.py in draw(self, renderer)
    168             if self.tick2On: self.tick2line.draw(renderer)
    169
--> 170         if self.label1On: self.label1.draw(renderer)
    171         if self.label2On: self.label2.draw(renderer)
    172

/usr/lib/python2.4/site-packages/matplotlib/text.py in draw(self, renderer)
    773     def draw(self, renderer):
    774         self.update_coords(renderer)
--> 775         Text.draw(self, renderer)
    776         if self.get_dashlength() > 0.0:
    777             self.dashline.draw(renderer)

/usr/lib/python2.4/site-packages/matplotlib/text.py in draw(self, renderer)
    315         angle = self.get_rotation()
    316
--> 317         bbox, info = self._get_layout(renderer)
    318         trans = self.get_transform()
    319         if rcParams['text.usetex']:

/usr/lib/python2.4/site-packages/matplotlib/text.py in _get_layout(self, 
renderer)
    198         baseline = None
    199         for line in lines:
--> 200             w, h, d = renderer.get_text_width_height_descent(
    201                 line, self._fontproperties, 
ismath=self.is_math_text(line))
    202             if baseline is None:

ValueError: need more than 2 values to unpack

I have tried both Tk and GTKagg backends with the same result.

Xavier.

-- 
############################################
Xavier Gnata
CRAL - Observatoire de Lyon
9, avenue Charles André
69561 Saint Genis Laval cedex
Phone: +33 4 78 86 85 28
Fax: +33 4 78 86 83 86
E-mail: gn...@ob...
############################################ 

Hi,
I am using Matplotlib to produce colormaps which I use with other
programs. I would like to produce a PNG file with the used colormap
(so that I can overlay). Rather than doing an imshow(<something>)
followed by colorbar, is there an easy way I could pass the colorbar
my cmap instance to have it plotted on its own? In essence, what I
want to do is to do a savefig, and get something along the lines of
what is shown here: <http://www.igidl.ul.pt/colorscale.gif>. I will
need to change the scale (i.e.,, the numbers :D) with each run.

So far, I have "cut+pasted" from a whole image, which is hardly convenient! :(

Cheers,
Jose