[Matplotlib-users] Convolution integral export as animation
Thomas Caswell
tcaswell at gmail.com
Sun May 19 18:24:30 EDT 2019
Try 'reply-all' instead?
Yes, that is controlled by the fps kwarg to `anim.save`.
Glad it is working!
Tom
On Sun, May 19, 2019 at 6:23 PM Erdem <farukerdemoncel at gmail.com> wrote:
> My reply does not show in the mail list. I have no idea why this happened
> but I simply use Gmail to reply. I used to use Gnus message reader with
> Emacs but I think it is not installed for now.
>
> Thanks now it works as expected!
>
> Is there a way to slow down animation a bit.
>
> Erdem
>
>
> Thomas Caswell <tcaswell at gmail.com>, 20 May 2019 Pzt, 01:05 tarihinde
> şunu yazdı:
>
>> Please don't drop the mailing list from the replies.
>>
>> Ah, I ran it by invoking the script in an IPython session where
>> `plt.ion()` has been called and `plt.show()` in non-blocking. If I run it
>> as as script I see what you descirbe!
>>
>> Removing the `plt.show()` calls from inside of the re-draw function
>> allows it to run end-to-end and write out the animation.
>>
>> Tom
>>
>> On Sun, May 19, 2019 at 5:59 PM Erdem <farukerdemoncel at gmail.com> wrote:
>>
>>> Thank you very much.
>>>
>>> My operating system is Ubuntu 18.04 LTS 64 bit. I've set up a virtual
>>> python environment and to activate I use this command.
>>>
>>> $ . venv/bin/activate
>>>
>>> I've saved source file as convolution py. To run the source code I use
>>> this command
>>>
>>> $ python convolution.py
>>>
>>> But rather than an animation I see only a plot of integral at t0=-2.00
>>>
>>> [image: convolution.png]
>>>
>>> I wait some time and nothing happens. I've also tried to close window a
>>> few times and the result is same.
>>>
>>> Since you may be able to get an mp4 file of the animation may it be
>>> because of some codecs are missing or may be a bug?
>>>
>>> Erdem
>>>
>>> Thomas Caswell <tcaswell at gmail.com>, 20 May 2019 Pzt, 00:17 tarihinde
>>> şunu yazdı:
>>>
>>>> Erdem,
>>>>
>>>> I do not understand your question. If I run that code I do get an mp4
>>>> file of the animation.
>>>>
>>>> Tom
>>>>
>>>>
>>>> On Sat, May 18, 2019 at 6:05 PM Erdem <farukerdemoncel at gmail.com>
>>>> wrote:
>>>>
>>>>> This example is taken from a tutorial
>>>>> <https://dspillustrations.com/pages/posts/misc/convolution-examples-and-the-convolution-integral.html> related
>>>>> to convolution integral.
>>>>>
>>>>> I would like to export this example as animation in mp4 format. So
>>>>> far, the code looks like this :
>>>>>
>>>>> import scipy.integrateimport numpy as npimport matplotlib.pyplot as pltimport matplotlib.animation as animation
>>>>> def showConvolution(t0,f1, f2):
>>>>> # Calculate the overall convolution result using Simpson integration
>>>>> convolution = np.zeros(len(t))
>>>>> for n, t_ in enumerate(t):
>>>>> prod = lambda tau: f1(tau) * f2(t_-tau)
>>>>> convolution[n] = scipy.integrate.simps(prod(t), t)
>>>>>
>>>>> # Create the shifted and flipped function
>>>>> f_shift = lambda t: f2(t0-t)
>>>>> prod = lambda tau: f1(tau) * f2(t0-tau)
>>>>>
>>>>> # Plot the curves
>>>>> plt.gcf().clear() # il
>>>>>
>>>>> plt.subplot(211)
>>>>> plt.gca().set_ymargin(0.05) # il
>>>>> plt.plot(t, f1(t), label=r'$f_1(\tau)$')
>>>>> plt.plot(t, f_shift(t), label=r'$f_2(t_0-\tau)$')
>>>>> plt.fill(t, prod(t), color='r', alpha=0.5, edgecolor='black', hatch='//') # il
>>>>> plt.plot(t, prod(t), 'r-', label=r'$f_1(\tau)f_2(t_0-\tau)$')
>>>>> plt.grid(True); plt.xlabel(r'$\tau$'); plt.ylabel(r'$x(\tau)$') # il
>>>>> plt.legend(fontsize=10) # il
>>>>> plt.text(-4, 0.6, '$t_0=%.2f$' % t0, bbox=dict(fc='white')) # il
>>>>>
>>>>> # plot the convolution curve
>>>>> plt.subplot(212)
>>>>> plt.gca().set_ymargin(0.05) # il
>>>>> plt.plot(t, convolution, label='$(f_1*f_2)(t)$')
>>>>>
>>>>> # recalculate the value of the convolution integral at the current time-shift t0
>>>>> current_value = scipy.integrate.simps(prod(t), t)
>>>>> plt.plot(t0, current_value, 'ro') # plot the point
>>>>> plt.grid(True); plt.xlabel('$t$'); plt.ylabel('$(f_1*f_2)(t)$') # il
>>>>> plt.legend(fontsize=10) # il
>>>>> plt.show() # il
>>>>> Fs = 50 # our sampling frequency for the plotting
>>>>> T = 5 # the time range we are interested in
>>>>> t = np.arange(-T, T, 1/Fs) # the time samples
>>>>> f1 = lambda t: np.maximum(0, 1-abs(t))
>>>>> f2 = lambda t: (t>0) * np.exp(-2*t)
>>>>>
>>>>> t0 = np.arange(-2.0,2.0, 0.05)
>>>>>
>>>>> fig = plt.figure(figsize=(8,3))
>>>>> anim = animation.FuncAnimation(fig, showConvolution, frames=t0, fargs=(f1,f2),interval=80)
>>>>>
>>>>> anim.save('animation.mp4', fps=30) # fps = frames per second
>>>>>
>>>>> plt.show()
>>>>>
>>>>>
>>>>> When I run the program I see the output of see the output of
>>>>> convolution integral at t0 = -0.20.
>>>>>
>>>>> [image: convolution.png]
>>>>>
>>>>> Is there a way to change t0 so that I'd like to able to save it as
>>>>> animation as in the tutorial
>>>>> <https://dspillustrations.com/pages/posts/misc/convolution-examples-and-the-convolution-integral.html> In
>>>>> the example t0 decreases from -2.0 to -1.95 etc the green curve is shifted
>>>>> right, and the area between curves, product increases. In the tutorial
>>>>> there is an html animation and I would like to save as mp4 file.
>>>>>
>>>>> I've also added source code as an attachment.
>>>>> _______________________________________________
>>>>> Matplotlib-users mailing list
>>>>> Matplotlib-users at python.org
>>>>> https://mail.python.org/mailman/listinfo/matplotlib-users
>>>>>
>>>>
>>>>
>>>> --
>>>> Thomas Caswell
>>>> tcaswell at gmail.com
>>>>
>>>
>>
>> --
>> Thomas Caswell
>> tcaswell at gmail.com
>>
>
--
Thomas Caswell
tcaswell at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/matplotlib-users/attachments/20190519/d86ee279/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: convolution.png
Type: image/png
Size: 36111 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/matplotlib-users/attachments/20190519/d86ee279/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: convolution.png
Type: image/png
Size: 36111 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/matplotlib-users/attachments/20190519/d86ee279/attachment-0003.png>
More information about the Matplotlib-users
mailing list