[Matplotlib-users] Embedding matplotlib into a Cocoa app (was Re: cocoa backend for matplotlib?)

[Josh M. <jos...@gm...>]

Hi Michael,

On 19/02/2006, at 1:51 PM, Michael Bentley wrote:
> Hi!
>
>> I have an application that is using PyObjC, matplotlib and scipy to
>> perform some image classification and feature extraction. I am now
>> attempting to use py2app to bundle it up into a single OS X .app.
>
> So I'm wondering -- have you already got a matplotlib backend  
> done?  I've just started work on such a project and don't want to  
> duplicate effort.
>
> Lemme know, so I don't waste my time! (that is, if you're willing  
> to share)
>
> -Michael

Yes, I do have this working. I can package up numpy/scipy/matplotlib  
into a .app using py2app, and distribute it. The resulting package is  
rather large and only compresses to 9 MB, but I haven't yet looked  
into what I can exclude from the package or using the Apple-supplied  
Python to reduce size.

I've attached the MatplotlibView class that I made, using code from  
the matplotlib Cocoa backend. (I'm not using the mouse event  
interaction yet, so I haven't tested it.) Just insert a NSView into  
your nib file and set the custom class to MatplotlibView. Then add  
the view as an outlet in your app delegate. (this is "imageView" in  
the following code.)

What I then do in my app delegate is first create the initial look.  
It ends up like this:

     def applicationDidFinishLaunching_(self, notification):
         self.imageView.figure.set_facecolor('w')
         self.imageView.axes.set_axis_off()
         self.imageView.updatePlot()

And then in response to user events, I have a function that updates  
the view:

     def showImage(self):
         axes = self.imageView.axes
         axes.clear()
	...
         if self.displayimage is 'original':
             axes.imshow(self.fullcolourimage, extent=[0,imsizex, 
0,imsizey])
	...
         axes.set_axis_off()
         axes.set_xticks([])
         axes.set_yticks([])

         axes.set_xlim(0, imsizex)
         axes.set_ylim(0, imsizey)
         axes.set_aspect(aspect='equal')

         self.imageView.figure.subplots_adjust 
(left=0,right=1,bottom=0,top=1)
         self.imageView.figure.set_facecolor('w')

         self.imageView.updatePlot()

This will now work fine as long as your app is created using  
"setup.py py2app --alias".
There are a few problems when you want to distribute it and just use  
the standalone "setup.py py2app".

First, in your setup.py you will need to include the matplotlib data  
files:

import matplotlib, glob
mpldata = ''.join([matplotlib.rcParams['datapath'], r'/*'])
matplotlibdata = glob.glob(mpldata)
setup_options['data_files'].append((u'matplotlibdata', matplotlibdata))

This will include the files in your application bundle. When the mpl- 
data directory was moved, the code that allowed any data directory to  
be used was commented out. I am not sure, but I think it applied to  
win32 only anyway. So what you need to do next is edit the matplotlib  
__init__.py, find the lines below "CODE ADDED TO SUPPORT PY2EXE", and  
uncomment them. Remove the "if sys.platorm == 'win32'" (or similar)  
condition as well, to give:

     if sys.frozen:  ### Remove "sys.platform == 'win32' and" from here
         path = os.path.join(os.path.split(sys.path[0])[0],  
'matplotlibdata')
         if os.path.isdir(path):  return path
         else:
             # Try again assuming sys.path[0] is a dir not a exe
             path = os.path.join(sys.path[0], 'matplotlibdata')
             if os.path.isdir(path): return path

There also seems to be a problem with the way numpy/scipy handles  
being frozen, so you need to actually expand the site-packages.zip  
into a site-packages directory in the same location (and then remove  
the zip). Eg:

unzip -q build/XXX.app/Contents/Resources/Python/site-packages.zip -d  
build/XXX.app/Contents/Resources/Python/site-packages
rm build/Bovillator.app/Contents/Resources/Python/site-packages.zip

And you are done! This should help with you embedding matplotlib into  
an application. I have also developed a mixin class that lets you  
easily add Cocoa bindings to Python code with only one line of code.  
If you want it let me know.

I am also posting this to the matplotlib user mailing list. Since  
these problem issues also might affect others, I will post a shorter  
version detailing these to matplotlib devel and numpy mailing lists.

Cheers,
Josh