matplotlib-users Mailing List for matplotlib

When you say "own axes", I presume you're using subplots.
You need to create your axes with different sizes (subplot creates
axes with same size), so that the height of images are equal when they
shrink to to fit in the axes box. You may create an axes with a given
size with following command

fig.add_axes([0.2, 0.08, 0.6, 0.04])

where the input list specifies the position of the axes in the
normalized figure coordinate.
But you need to manually calculate the correct axes position.

In the example directory of the mpl svn, there are little helper
classes I wrote (axes_grid.py, axes_divider.py).
The link below shows a little example how you can use them.

http://abitofpythonabitofastronomy.blogspot.com/2009/02/images-side-by-side-in-mpl.html

-JJ



On Tue, Feb 17, 2009 at 9:43 AM, Eric Jonas <jo...@mi...> wrote:
> I searched for a considerable amount of time this weekend, but have yet
> to figure out how to do the following:
>
> I want to plot several M_i x N images side-by-side on a figure. In
> particular, something like follows:
>
>
> |-----------------|   |--------|     |---|
> |                 |   |        |     |   |
> |                 |   |        |     |   |
> |                 |   |        |     |   |
> |                 |   |        |     |   |
> |                 |   |        |     |   |
> |                 |   |        |     |   |
> |                 |   |        |     |   |
> |                 |   |        |     |   |
> -------------------   ----------     -----
>
> That is, while each image has the same height, the widths
> (in pixel values) are different. At the moment, I am plotting
> each image in its own axes, but the problem appears to be that
> the "fatter" image is being scaled down to the point
> of being too small (and so that all subfigure sections are roughly the
> same size).
>
> I want each image to eventually have independent sets of labels
> along the X axis, so I can't just combine them all into one big image.
> Might anyone have any idea how to pull this off?
>                        ...Eric
>
>
>
> ------------------------------------------------------------------------------
> Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA
> -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise
> -Strategies to boost innovation and cut costs with open source participation
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>

Davide Lazzati wrote:
> On Mon, Feb 16, 2009 at 8:13 PM, Jeff Whitaker <js...@fa...> wrote:
>   
>> Davide Lazzati wrote:
>>     
>>>  Hi,
>>>
>>> I'm trying to rum python and matlpotlib on a remote mac host from my
>>> mac laptop. Both have Mac OS/X 10.5.6 and I'm using ssh -Y ...
>>>
>>> However, the graphic window does not appear and, when I run p.show()
>>> everything gets stuck.
>>>
>>> Any insight?
>>>
>>> Thanks
>>>
>>>       
>> Davide:  This will only work if you use an X11-based backend (like GTK Agg),
>> since only X11 is forwarded over SSH.  If you're using a mac-native backend,
>> the window is popping up on your mac's screen when you do show().
>>
>> -Jeff
>>     
>
> I've tried to use GTKAgg and it gives me an error message . I'm now
> running on the MacOSX backend and the graphic window appears on the
> remote screen (where pyton is running) rather than on the local one
> (in front of which I am sitting). Any idea on how to open the graphic
> window with a MacOSX or TkAgg backends on the local screen while
> python is running remote?
>
> Thanks again
> Davide
>
>
>
>   
Davide:  As I said before, you have to use a backend compiled with X11 
support if you want to ssh to run matplotlib remotely.  You probably 
don't have one, since TkAgg is native OS X  and you probably don't have 
the pre-requisites installed to build the GTKAgg backend.  You have two 
choices:

1) install all the pre-requisites for the GTKAgg backend (don't know 
what they are offhand, but they include at least gtk2, glib and 
pygtk2).  Package management systems like fink or macports can help with 
this.

2) use the screen-sharing feature of Leopard to remote control your mac 
instead of ssh.  Then you will see exactly what is on the screen of the 
remote mac.  This will work with any backend, but may be slow and/or 
complicated if you have firewalls in between the macs.

I do this routinely by using the python, pygtk2 and matplotlib packages 
installed by macports,   Never had much luck with remote screen sharing 
because of firewall issues.

-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

On Mon, Feb 16, 2009 at 8:13 PM, Jeff Whitaker <js...@fa...> wrote:
> Davide Lazzati wrote:
>>
>>  Hi,
>>
>> I'm trying to rum python and matlpotlib on a remote mac host from my
>> mac laptop. Both have Mac OS/X 10.5.6 and I'm using ssh -Y ...
>>
>> However, the graphic window does not appear and, when I run p.show()
>> everything gets stuck.
>>
>> Any insight?
>>
>> Thanks
>>
>
> Davide:  This will only work if you use an X11-based backend (like GTK Agg),
> since only X11 is forwarded over SSH.  If you're using a mac-native backend,
> the window is popping up on your mac's screen when you do show().
>
> -Jeff

I've tried to use GTKAgg and it gives me an error message . I'm now
running on the MacOSX backend and the graphic window appears on the
remote screen (where pyton is running) rather than on the local one
(in front of which I am sitting). Any idea on how to open the graphic
window with a MacOSX or TkAgg backends on the local screen while
python is running remote?

Thanks again
Davide



-- 
=====================================
Davide Lazzati, Assistant Professor
NCSU, Dept. of Physics, Riddick Hall
Office 400E, tel (919) 513 0926
Raleigh, NC, 27695-8202
=====================================

I searched for a considerable amount of time this weekend, but have yet
to figure out how to do the following: 

I want to plot several M_i x N images side-by-side on a figure. In
particular, something like follows: 


|-----------------|   |--------|     |---|
|                 |   |        |     |   |
|                 |   |        |     |   |
|                 |   |        |     |   |
|                 |   |        |     |   |
|                 |   |        |     |   |
|                 |   |        |     |   |
|                 |   |        |     |   |
|                 |   |        |     |   |
-------------------   ----------     -----

That is, while each image has the same height, the widths
(in pixel values) are different. At the moment, I am plotting
each image in its own axes, but the problem appears to be that
the "fatter" image is being scaled down to the point
of being too small (and so that all subfigure sections are roughly the
same size). 

I want each image to eventually have independent sets of labels
along the X axis, so I can't just combine them all into one big image. 
Might anyone have any idea how to pull this off? 
			...Eric

Hi,

I think your situation is different from mine, but just thought it might help.

I have a server running linux and I use mac pro to connect to the
server and export graphics from the linux server. I could get my mac
pro to display the graphics from the linux server only after I start
X11 on my mac pro and then use ssh -X to connect to the linux server.

Wonder if you also have to do something like that when you connect.
First, start X11 on your mac and then connect to your other mac (linux
in my case though).

Cheers,
Chaitanya.

On Tue, Feb 17, 2009 at 2:01 AM, Davide Lazzati <dla...@gm...> wrote:
>  Hi,
>
> I'm trying to rum python and matlpotlib on a remote mac host from my
> mac laptop. Both have Mac OS/X 10.5.6 and I'm using ssh -Y ...
>
> However, the graphic window does not appear and, when I run p.show()
> everything gets stuck.
>
> Any insight?
>
> Thanks
>
> ------------------------------------------------------------------------------
> Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA
> -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise
> -Strategies to boost innovation and cut costs with open source participation
> -Receive a $600 discount off the registration fee with the source code: SFAD
> http://p.sf.net/sfu/XcvMzF8H
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

Here is the fix, thanks to Eric's reply to my colorbar posting!

The modified code to update the image:

            ###self.myImage =
self.axes.imshow(self.image_data,aspect='auto',extent=[self.pageOffset,s
elf.pageOffset+self.pageSizeSamps,0,self.numChans])

            self.myImage.set_array(self.image_data)

 
self.myImage.set_extent([self.pageOffset,self.pageOffset+self.pageSizeSa
mps,0,self.numChans])

 
self.cbar.set_clim(vmin=self.image_data.min(),vmax=self.image_data.max()
)

            self.cbar.draw_all()

            self.canvas.draw()

 

Thanks to all for the help!

amb

________________________________

From: mat...@li...
[mailto:mat...@li...] On Behalf Of
Lewis, Ambrose J.
Sent: Monday, February 16, 2009 7:15 AM
To: mat...@li...
Subject: [Matplotlib-users] imshow extent & toolbar zoom??

 

Hi All:

Thanks to Michael & Ryan, I got my imshow call displaying the correct
data range on the x axis!  

However, when I now use a toolbar to zoom the image, I'm getting a
divide by zero error (see traceback below)

I'm using Python 2.5.2, wx 2.8.7.1, and Matplotlib 0.98.5.2 on win32.

Thanks for your (hopefully) continued patience with these newbie
questions!

amb

 

Here is the call to imshow that I modified:

self.myImage =
self.axes.imshow(self.image_data,aspect='auto',extent=[self.pageOffset,s
elf.pageOffset+self.pageSizeSamps,self.numChans,1])

from:

self.myImage = self.axes.imshow(self.image_data,aspect='auto')

The old version zooms just fine with no error.  This code is called in a
menu event handler

 

Here is how I created the figure & toolbar:

 
########################################################################
#########################

    def SetupPlot(self):

        self.figure = Figure()

        self.axes = self.figure.add_subplot(111)

        self.canvas = FigureCanvas(self, -1, self.figure)

        self.data = np.zeros((self.numChans,self.pageSizeSamps))

        self.myImage = self.axes.imshow(self.data,aspect='auto')

        self.sizer.Add(self.canvas,pos=(1,1))

        self.add_toolbar()  

 

 
########################################################################
#########################

    def add_toolbar(self):

        self.toolbar = NavigationToolbar2Wx(self.canvas)

        self.toolbar.Realize()

        # On Windows platform, default window size is incorrect, so set

        # toolbar width to figure width.

        tw, th = self.toolbar.GetSizeTuple()

        fw, fh = self.canvas.GetSizeTuple()

        # By adding toolbar in sizer, we are able to put it at the
bottom

        # of the frame - so appearance is closer to GTK version.

        # As noted above, doesn't work for Mac.

        self.toolbar.SetSize((fw, th))

        self.sizer.Add(self.toolbar,pos=(2,1))

        # update the axes menu on the toolbar

        self.toolbar.update()

 

Here is the error Traceback:

Traceback (most recent call last):

  File
"C:\Python25\Lib\site-packages\matplotlib\backends\backend_wx.py", line
1

225, in _onLeftButtonUp

    FigureCanvasBase.button_release_event(self, x, y, 1, guiEvent=evt)

  File "C:\Python25\Lib\site-packages\matplotlib\backend_bases.py", line
1198, i

n button_release_event

    self.callbacks.process(s, event)

  File "C:\Python25\Lib\site-packages\matplotlib\cbook.py", line 155, in
process

 

    func(*args, **kwargs)

  File "C:\Python25\Lib\site-packages\matplotlib\backend_bases.py", line
2048, i

n release_zoom

    self.draw()

  File "C:\Python25\Lib\site-packages\matplotlib\backend_bases.py", line
2070, i

n draw

    self.canvas.draw()

  File
"C:\Python25\Lib\site-packages\matplotlib\backends\backend_wxagg.py",
lin

e 60, in draw

    FigureCanvasAgg.draw(self)

  File
"C:\Python25\Lib\site-packages\matplotlib\backends\backend_agg.py", line

279, in draw

    self.figure.draw(self.renderer)

  File "C:\Python25\Lib\site-packages\matplotlib\figure.py", line 772,
in draw

    for a in self.axes: a.draw(renderer)

  File "C:\Python25\Lib\site-packages\matplotlib\axes.py", line 1545, in
draw

    im.draw(renderer)

  File "C:\Python25\Lib\site-packages\matplotlib\image.py", line 233, in
draw

    im = self.make_image(renderer.get_image_magnification())

  File "C:\Python25\Lib\site-packages\matplotlib\image.py", line 220, in
make_im

age

    rx = widthDisplay / numcols

ZeroDivisionError: float division

________________________________

From: mat...@li...
[mailto:mat...@li...] On Behalf Of
Lewis, Ambrose J.
Sent: Saturday, February 14, 2009 7:07 AM
To: mat...@li...
Subject: [Matplotlib-users] x axis & imshow...

 

Thanks Michael & Ryan!
Worked great!
amb


-----Original Message-----
From: Michael Droettboom [mailto:md...@st...]
Sent: Fri 2/13/2009 1:14 PM
To: Lewis, Ambrose J.
Cc: mat...@li...
Subject: Re: [Matplotlib-users] x axis & imshow...

You can pass "extent=(left, right, bottom, top)" to imshow to specify
what the pixels in the array correspond to in data space.

Mike

Lewis, Ambrose J. wrote:
>
> Hi All:
>
> I'm working on a wxPython GUI that uses matplotlib.
>
> This program reads "chunks" of a data file into a numpy array and than
> plots it using imshow.
>
> The first chunk works great. But, when I load chunks 2 to N, how can I
> specify the different values for the labels on the x axis?
>
> I tried using "axes.set_xlim". This did reposition the x axis as
> hoped, but the data is always being drawn back at the "zero" offset.
>
> Is there a way to tell the axis to map the array to a different x
range?
>
> I can't read the whole file at once, it's just too big
>
> THANXS
>
> amb
>
>
------------------------------------------------------------------------
>
>
------------------------------------------------------------------------
------
> Open Source Business Conference (OSBC), March 24-25, 2009, San
Francisco, CA
> -OSBC tackles the biggest issue in open source: Open Sourcing the
Enterprise
> -Strategies to boost innovation and cut costs with open source
participation
> -Receive a $600 discount off the registration fee with the source
code: SFAD
> http://p.sf.net/sfu/XcvMzF8H
>
------------------------------------------------------------------------
>
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>  

--
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

Thanks Eric...This approach also fixed my zooming issue in my other
post!!!
amb

-----Original Message-----
From: Eric Firing [mailto:ef...@ha...] 
Sent: Monday, February 16, 2009 4:12 PM
To: Lewis, Ambrose J.
Cc: mat...@li...
Subject: Re: [Matplotlib-users] updating colorbar to match new image
data...

Lewis, Ambrose J. wrote:
> Hi All:
> 
> I'm using the following code to create and display an image with a 
> colorbar.  Later on, I read data from a file and update the image.  
> 
> How do I refresh the colorbar to match this new data?  Uncommenting
the 
> line in my "ReadFromFile" call below generates a new colorbar.  I'd
just 
> like to replace the existing one to match the new data.
> 
> I'm using Python 2.5.2, wx 2.8.7.1, and Matplotlib 0.98.5.2 on win32.
> 
> THANXS
> 
> amb
> 
>  
> 
>     
>
########################################################################
#########################
> 
>     def SetupPlot(self):
> 
>         self.figure = Figure()
> 
>         self.axes = self.figure.add_subplot(111)
> 
>         self.canvas = FigureCanvas(self, -1, self.figure)
> 
>         self.data = np.zeros((self.numChans,self.pageSizeSamps))
> 
>         self.myImage = self.axes.imshow(self.data,aspect='auto')
> 
>         self.cbar = 
>
self.figure.colorbar(self.myImage,ticks=[0,100],orientation='horizontal'
)
> 
>         self.sizer.Add(self.canvas,pos=(1,1),span=(1,2))
> 
>         self.add_toolbar() 
> 
>    
>
########################################################################
#########################
> 
>     def ReadFromFile(self):
> 
>         if self.filename=="":
> 
>             print "pick a file first!"
> 
>         else:
> 
>             # bunch of code to read from file via numpy fromfile lives
here...
> 
>             self.image_data = abs(fftshift(data,axes=[0]))
> 
>             self.myImage = 
>
self.axes.imshow(self.image_data,aspect='auto',extent=[self.pageOffset,s
elf.pageOffset+self.pageSizeSamps,0,self.numChans])
> 
>             #self.cbar = 
> self.figure.colorbar(self.myImage,orientation='horizontal')
> 
>             self.canvas.draw()

The problem is that you are generating a new mappable, so the old 
colorbar is disconnected from the new image.  I haven't tested with an 
example, but it looks like you should be able to replace the calls in 
ReadFromFile to imshow with method calls on the original image object. 
Try using self.myImage.set_data, self.myImage.set_extent, and 
self.myImage.changed.  The latter will tell the colorbar to update
itself.

Eric

Davide Lazzati wrote:
>   Hi,
>
> I'm trying to rum python and matlpotlib on a remote mac host from my
> mac laptop. Both have Mac OS/X 10.5.6 and I'm using ssh -Y ...
>
> However, the graphic window does not appear and, when I run p.show()
> everything gets stuck.
>
> Any insight?
>
> Thanks
>   

Davide:  This will only work if you use an X11-based backend (like GTK 
Agg), since only X11 is forwarded over SSH.  If you're using a 
mac-native backend, the window is popping up on your mac's screen when 
you do show().

-Jeff

  Hi,

I'm trying to rum python and matlpotlib on a remote mac host from my
mac laptop. Both have Mac OS/X 10.5.6 and I'm using ssh -Y ...

However, the graphic window does not appear and, when I run p.show()
everything gets stuck.

Any insight?

Thanks