Cannot remove streamplot arrow heads from Matplotlib axes

Question

How can I remove a streamplot from a Matplotlib plot without clearing everything (i.e. not using plt.cla() or plt.clf())?

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plt.streamplot() returns a StreamplotSet (streams in the following example), which contains the stream lines (.lines) and arrow heads (.arrows).

Calling streams.lines.remove() removes the streamlines as expected.

However, I couldn’t find a way to remove the arrow heads: stream.arrows.remove() raises a NotImplementedError, and stream.arrows.set_visible(False) has no effect.

import matplotlib.pyplot as plt
import numpy as np

# Generate streamplot data
x = np.linspace(-5, 5, 10)
y = np.linspace(-5, 5, 10)
u, v = np.meshgrid(x, y)

# Create streamplot
streams = plt.streamplot(x, y, u, v)

# Remove streamplot
streams.lines.remove()  # Removes the stream lines
streams.arrows.set_visible(False)  # Does nothing
streams.arrows.remove()  # Raises NotImplementedError

The following figure illustrates the example. Left: streamplot, right: remaining arrow heads.

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For context, I’m trying to add streamlines to an existing imshow animation (built with matplotlib.animation.FuncAnimation). In this setup, only the image data are updated at each frame, and I can’t clear and redraw the full plot.

Answer 1

This solution seems to work and is inspired from this answer. There are two ways:

1. Remove the arrow patch
2. Set the alpha parameter to 0

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streams = plt.streamplot(x, y, u, v)

ax = plt.gca()

for art in ax.get_children():
    if not isinstance(art, matplotlib.patches.FancyArrowPatch):
        continue
    art.remove()        # Method 1
    # art.set_alpha(0)  # Method 2