How to export plots from matplotlib with transparent background?
matplotlib, plot, python, transparency
Solution
Use the matplotlib `savefig` function with the keyword argument `transparent=True` to save the image as a png file.
In [28]: import numpy as np
In [29]: from matplotlib.pyplot import plot, savefig
In [30]: x = np.linspace(0,6,31)
In [31]: y = np.exp(-0.5*x) * np.sin(x)
In [32]: plot(x, y, 'bo-')
Out[32]: [<matplotlib.lines.Line2D at 0x3f29750>]
In [33]: savefig('demo.png', transparent=True)
Result:
Of course, that plot doesn't demonstrate the transparency. Here's a screenshot of the PNG file displayed using the ImageMagick `display` command. The checkerboard pattern is the background that is visible through the transparent parts of the PNG file.
Problem
I am using matplotlib to make some graphs and unfortunately I cannot export them without the white background. In other words, when I export a plot like this and position it on top of another image, the white background hides what is behind it rather than allowing it to show through. How can I export plots with a transparent background instead?