Matplotlib - Python- GetDist tool - Overlapping 2 triangle plots (triplots) by calling twice the plot function: issue of visible priority between both

Question

In python3, I am faced to 2 issues using the tool GetDist tool to produce triplot of covariance matrix.

1) Currently, I can plot 2 covar

Answer 1

It's kind of hacky but you can change the zorder for the contours afterwards. For this we take the lower triangular plots and set the zorder properties of the path and line collections. They appear in the following order:

1. filled area for 2 sigma of 1st sample
2. filled area for 1 sigma of 1st sample
3. contour lines for 1st sample
4. filled area for 2 sigma of 2nd sample
5. filled area for 1 sigma of 2nd sample
6. contour lines for 2nd sample

Originally all filled areas have zorder 1 and all lines 2. We set them as required to e.g. 17, 19, 21, 18, 20, 21.

Example:

from getdist import plots, gaussian_mixtures
samples1, samples2 = gaussian_mixtures.randomTestMCSamples(ndim=4, nMCSamples=2)
g = plots.get_subplot_plotter()
g.triangle_plot([samples1, samples2], filled=True, legend_labels = ['Contour 1', 'Contour 2'])

for ax in g.fig.axes:
    geo = ax.get_geometry()
    if (geo[2]-1) // geo[0] > (geo[2]-1) % geo[0]:
       for c,z in zip(ax.collections, [17,19,21,18,20,21]):
           c.zorder = z