save_animation on 2 axis simultaneously

[patquem]

Hello,

How to create a gif animation of 2 subplots iterating simultaneously ?
Is there a way to have a 'global' controler for both axis ?
(in the example below, only the first axis iterates due to save_animation linked to the 1rst axis controler).

Any idea ?
Thanks.
Patrick

[patquem]

Going back to the primary function FuncAnimation seems to be a good and simple solution (in this case) :

from __future__ import division
from matplotlib import pyplot as plt
from matplotlib.animation import FuncAnimation, PillowWriter

fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(18, 6))
ax1.set_title('Amplitude')
ax1.set_xlabel(xlabel)
ax1.set_ylabel(ylabel)
ax2.set_title('Phase')
ax2.set_xlabel(xlabel)
ax2.set_ylabel(ylabel)

img1 = ax1.imshow(amplitude[..., 0], cmap=plt.get_cmap('cool'), vmin=ampli_min, vmax = ampli_max, extent=extent)
img2 = ax2.imshow(phase[..., 0], cmap=plt.get_cmap('spring'), vmin=phase_min, vmax = phase_max, extent=extent)

def plot(k):
    img1.set_array(amplitude[..., k])
    img2.set_array(phase[..., k])
    return [img1, img2]

anim = FuncAnimation(fig, plot, 128, blit=True)
anim.save("movie2.gif", writer=PillowWriter(fps=24))
plt.show()

[ianhi]

Hi @patquem

I saw your question on discourse as well so linking that here: https://discourse.matplotlib.org/t/mpl-interactions-save-animation-on-2-axis-simultaneously/22077/

The relevant section of the docs is https://mpl-interactions.readthedocs.io/en/stable/examples/Usage-Guide.html#Only-Using-some-of-the-parameters-+-specifying-axes

In your case you need to do:

controls = iplt.imshow(ampli2d, k=k, ax=ax1)
_ = iplt.imshow(phase2d, ax=ax2, controls=controls) # <- THIS IS THE IMPORTANT CHANGE
anim = controls.save_animation(“plot-2.gif”, fig, “k”, interval=35, N_frames=100)

[patquem]

Hi @ianhi ,
Excellent. I missed this :(
Thanks you very much

[ianhi]

I'm sorry the docs weren't more clear! I think they definitely could be improved to make stuff like this easier to find.

If you have any suggestions on what would have made this easier for you to find this feel free to let me know :)

[patquem]

Don't apologize.
The documentation is very clear (with numerous examples/illustrations).
I should have had to pass more time on it.

[ianhi]

One other thing to note here is that it looks like you're mostly using mpl-interactions to index through a pre made array right? There are two easy ways to do that that don't involve a function:

Use the indexer convenience function (https://mpl-interactions.readthedocs.io/en/stable/autoapi/mpl_interactions.indexer.html?highlight=indexer#mpl_interactions.indexer). In your case it should be indexer(amplitude, 'k', -1)

2. If you put the k axis as the zero axis then you can use hyperslicer which knows how to automatically create sliders for indexing through stacks of images: https://mpl-interactions.readthedocs.io/en/stable/examples/hyperslicer.html