https://matplotlib.org/2.0.1/api/pyplot_api.html#matplotlib.pyplot.subplot

says "If a number the ratio of x-unit/y-unit in screen-space".

https://matplotlib.org/2.0.1/api/_as_gen/matplotlib.axes.Axes.set_aspect.html#matplotlib.axes.Axes.set_aspect

says "num | a circle will be stretched such that the height is num times the width".

This looks to me like x and y are the other way round. Is this right?