matplotlib animation adding weird box to corner of plot in MPEG

Question

I'm using matplotlib animation package to create an animated graph.

I'm using celluloid package to simplify things, and so I can draw a seaborn plot.

I can't figure out why a little box is appearing in the saved video:

Here is my code:

#%%
sns.set()
plt.style.use('seaborn-pastel')
sns.set_style('white',
              {"axes.axisbelow": False,
               "font.sans-serif": ['Futura'],
               })
sns.set_context("paper", font_scale=1.5)


#%%
fig = plt.figure()
camera = Camera(fig)

for i in range(0, len(height_sample_data)+2, 2):
    plot1 = sns.scatterplot(x=0, y=height_sample_data.Height[:i],
                            hue=height_sample_data.col, alpha=0.75)
    sns.despine(bottom=True)
    plt.xticks([])
    plt.xlabel("")
    plt.ylabel("Height (cm)")
    plt.legend("", frameon=False)
    plt.text(-.1, 140, f"{i}/{len(height_sample_data)} DataPoints Plotted")
    plt.xlim(-0.5, 0.5)
    plt.ylim(130, 220)
    camera.snap()
anim = camera.animate(blit=True)
anim.save('Chapter6/Animations/AddingDots.mp4')

I ran almost the same plot (sans animation) and saved it to a png rather than MPEG, and the box was gone, so it seems to be something to do with the animation. I thought at first it was the legend outline, but I'm hiding that properly I think.

Edit: I'm on mac (Catalina) and using ffmpeg as mpeg saver, installed through homebrew.

score 0 · Answer 1 · answered Mar 12 '20 at 06:16

I'm an idiot. It was in fact the legend. My original code to remove legend was meant to be used with the ax (axes) object. From plt, I needed to call

plt.legend("", frameon=False)

This gets rid of the frame that was causing the little square. The "" gets rid of contents, but not frame.

matplotlib animation adding weird box to corner of plot in MPEG

1 Answers1