Let's say we have a transform tr that takes 2-dimensional input and returns 2-dimensional input. If I do:

plt.plot(x, y, transform=tr)

x and y will get passed to tr.transform. Now in some cases the transformation may require 3 coordinates and return 2 'final' coordinates to be plotted (e.g. astrofrog/wcsaxes#148).

For example I might have a transformation that takes longitude, latitude, and altitude and translates these into a 2-d position in a satellite image. In this case if I want to plot points I'd like to be able to do:

plt.plot(longitude, latitude, altitude, transform=tr)

However this doesn't work (and I tried a few other ways to). Is there a way to get this to work, and if not, could it be considered as a feature request? Just to be clear, the transform would always return two coordinates, but could take any arbitrary number of inputs.