The python plotting library matplotlib will by default add margins to any plot that it generates. They can be reduced to a certain degree through some options of
pad_inches=0. Even with those options, some margins will always remain, though.
If a plot generated by matplotlib is to be used in conjunction with pgfplots and the
addplot graphics feature, those margins need to be predictable (and ideally non-existent).
Q: How can these margins be got rid of completely?