Editing Code Guide (section)

===Plotting and Animating===
Plotting data is simple using matplotlib and the documentation
is full of information and examples on how to fully customise
your plots. The following examples shows how simple it is to get
a quick plot:


<code>
1 import matplotlib as mpl

2 mpl.use(’TkAgg’) # macOS only!

3 import matplotlib.pyplot as plt

4

5 data = [some_data]

6

7 plt.plot(data)

8 plt.show()
</code>


Animating is a bit trickier and I found the examples confusing
at first so here is an example of how to animate some data:


<code>
1 import ma tplot l ib as mpl

2 mpl.use(’TkAgg’)

3 import matplotlib.pyplot as plt

4 import matplotlib.animation as animation

5

6 data = [some_data]

7 fig = plt.figure()

8 axis = fig.add_axes([0.1, 0.1, 0.8, 0.7])

9

10 def animate (frames, kwargs):

11 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;plt.plot(data[frames])

12

13 ani = animation.FuncAnimation(fig, animate, interval = 1000, frames = len(data), kwargs = None)

14 ani.save(’filename.mp4’)

15 plt.show()
</code>


Basically, the FuncAnimation function creates the animation
using the user written function "animate" to create all the frames
of the animation. The frames parameter is a generator (similar
to a list of a range, e.g. frames = 10 is similar to, but not the
same as frames = range(0, 10)). The interval between frames in
this example is 1000ms, or 1s. The animate function can be as
complex as necessary and as long as the frames input changes
the plot, there will be an animation video at the end. I found
that the video file that is created works better if the frames are
short in duration (20ms or so). This means that an animation will
usually need a large number of frames.