Re: [Matplotlib-users] How to create a movie?? (from matlab code)

[Gousios G. <gg...@wi...>]

Στις 21/01/2012 07:05 μμ, ο/η Tony Yu έγραψε:
>
>
> On Sat, Jan 21, 2012 at 11:31 AM, Gousios George 
> <gg...@wi... <mailto:gg...@wi...>> wrote:
>
>     Στις 21/01/2012 04:54 μμ, ο/η Tony Yu έγραψε:
>>
>>
>>     On Sat, Jan 21, 2012 at 9:07 AM, Gousios George
>>     <gg...@wi... <mailto:gg...@wi...>> wrote:
>>
>>         Hello , i have the following code in matlab and trying to do
>>         it in
>>         matplotlib.
>>
>>         I have this code in matlab (in a function showGraphs):
>>         ...
>>         m = size(myList, 3);
>>         for k = 1:m
>>             g = myList(:, :, k);
>>             image(g + 1)
>>             axis off
>>             axis square
>>             M(k) = getframe;
>>         end;
>>
>>         and in another file (another function):
>>         ...
>>         M = showGraphs(grids)
>>         movie(M, 1)
>>
>>
>>
>>         I did so far:
>>
>>         def showGraphs(data):
>>             data=sc.array([data])
>>             n=sc.shape(data)[2]
>>             for k in range(n):
>>                 mydata=data[:,:,k]
>>                 #plt.imshow(mydata+1)    -->> this doesn't work
>>
>>         Also ,in order to do the animation :
>>
>>         grids=...(result from another function)
>>         result=showGraph(grids)
>>         fig=plt.figure()
>>         ani=animation.FuncAnimation(fig,result,interval=30,blit=True)
>>         plt.show()
>>
>>         Right now the program says "TypeError: 'NoneType' object is not
>>         callable" (it has errors in the animation call)
>>
>>         What should be my approach to this in order to have the
>>         animation?
>>
>>         Thank you!
>>
>>
>>     You're getting that error because the second argument to
>>     FuncAnimation (`result` in your example) should be a function
>>     (not always; see example 2 linked below). Right now, if your
>>     `showGraphs` function is defined in full, it returns a value of
>>     None, which gets saved to `result` (hence the error).
>>
>>     You should take a look at some of the image animation examples
>>     (ex1
>>     <http://matplotlib.sourceforge.net/examples/animation/dynamic_image.html>,
>>     ex2
>>     <http://matplotlib.sourceforge.net/examples/animation/dynamic_image2.html>).
>>
>>     -Tony
>>
>
>     I did now :
>
>
>     def showGraphs(data):
>         data=sc.array([data])
>         n=sc.shape(data)[2]
>         ims=[]
>
>         for k in range(n):
>             mydata=data[:,:,k]
>             im=plt.imshow(mydata+1)
>             ims.append([im])
>         return ims
>
>     and now it gives me "TypeError: Invalid dimensions for image data.
>
>
> Please post short, but executable examples when possible. I'm not sure 
> what your data looks like, but your call to `sc.array` is strange (I'm 
> not sure why you have square brackets, which effectively adds an 
> unnecessary dimension to your data).
>
> The code attached below should work.
>
> Cheers,
> -Tony
>
> import numpy as np
> import matplotlib.pyplot as plt
> from matplotlib.animation import ArtistAnimation
>
>
> fig = plt.figure()
>
> def showGraphs(data):
>     data = np.asarray(data) # unnecessary in this example
>     n = np.shape(data)[2]
>
>     ims = []
>     #for mydata in np.rollaxis(data, -1):
>     for k in range(n):
>         mydata = data[:, :, k]
>         im = plt.imshow(mydata)
>         ims.append([im])
>     return ims
>
> # 5 frames of a random 20 x 20 image
> data = np.random.uniform(size=(20, 20, 5))
> ims = showGraphs(data)
>
> ani = ArtistAnimation(fig, ims)
> plt.show()
Now,it gives me 2 figures (why 2?) but empty.(maybe i didn't convert 
right the matlab code below?)
The data in the showGraphs function is the result from this function (in 
matlab):
.........
grids = zeros(n, n, t + 1);
grids(:, :, 1) = rest;
for i = 2:(t + 1)
     Extended = extendLat1(rest);
     rest = applyExtended(Extended);
     grids(:, :, i) = rest;
end;

And i did this in python:

    grids=sc.zeros((area,area,t+1))
     rest=grids[:,:,0]
     for i in range(1,t):
         extended=extend(rest)
         rest=apply_extend(extended)
         grids[:,:,i]=rest
     return grids

Thanks for helping!