Matplotlib animate fill_between shape

Question

I am trying to animate a fill_between shape inside matplotlib and I don\'t know how to update the data of the PolyCollection. Take this simple example: I have two lines and

Answer 1

initialize pyplot interactive mode

import matplotlib.pyplot as plt

plt.ion()

use the optional label argument when plotting the fill:

plt.fill_between(
    x, 
    y1, 
    y2, 
    color="yellow", 
    label="cone"
)

plt.pause(0.001) # refresh the animation

later in our script we can select by label to delete that specific fill or a list of fills, thus animating on a object by object basis.

axis = plt.gca()

fills = ["cone", "sideways", "market"]   

for collection in axis.collections:
    if str(collection.get_label()) in fills:
        collection.remove()
        del collection

plt.pause(0.001)

you can use the same label for groups of objects you would like to delete; or otherwise encode the labels with tags as needed to suit needs

for example if we had fills labelled:

"cone1" "cone2" "sideways1"

if "cone" in str(collection.get_label()):

would sort to delete both those prefixed with "cone".

You can also animate lines in the same manner

for line in axis.lines: