How do I remove a matplotlib fill from my plot

Question

I was able to add a fill of a triangle onto my plot by following the format:

ax.fill([x1, x2, x3], [y1, y2, y3], 'r', alpha = 0.5)

But when I want to reuse the graph to show a different dataset, I cannot seem to be able to remove the fill object. My plot contains markers, lines and a single fill. What would be the best way to remove this fill?

Currently, when I want to reset my graph, I use:

EraseMarkers() # To remove markers
for i in ax.get_lines():
    i.remove() # To remove lines

I tried use matplotlib’s ax.cla() function, but this doesn’t satisfy my needs as it clears the entirety of my plot in which I would like to keep the image that I set as a background and other settings. Here is the code for setting up my plot:

fig = Figure(figsize = (9, 3.8), dpi = 100)
img = plt.imread('Rink2.png')
ax = fig.add_subplot(111)
img = ax.imshow(img, extent=[-100, 100, -42.5, 42.5])
ax.get_xaxis().set_visible(False)
ax.get_yaxis().set_visible(False)
ax.axis('off')

I’d love to know an easier way to remove all plotted objects (Markers, lines & fill) without erasing my background and settings. Or just a way to remove the fill.

Asked By: KG_

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Source

Answer 1

It is possible to remove an element arbitrary element A from a plot by using A.remove().
To do that, when you call ax.fill you can store the return of this function to a variable, as

filled = ax.fill([x1, x2, x3], [y1, y2, y3], 'r', alpha = 0.5)

to remove it you can than use:

for f in filled:
    f.remove()

see the minimum example below:

fig = plt.Figure(figsize=(10,10))
ax = fig.add_subplot(111)

x1, x2, x3 = 1, 2, 3
y1, y2, y3 = 0, 2, 0

fill = ax.fill([x1, x2, x3], [y1, y2, y3], 'r', alpha = 0.5)

ax.get_xaxis().set_visible(False)
ax.get_yaxis().set_visible(False)

fig.savefig('test1.png')

for f in fill:
    f.remove()

fig.savefig('test2.png')

test1.png:

test2.png:

PS: when adding the figure, is generally best to use the built-in constructors such as plt.subplots or plt.figure instead of accessing the class directly as in Figure

Answered By: Rafael Menezes

How do I remove a matplotlib fill from my plot

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