matplotlib/seaborn: first and last row cut in half of heatmap plot

Question

When plotting heatmaps with seaborn (and correlation matrices with matplotlib) the first and the last row is cut in halve. This happens also when I run this minimal code exa

Answer 1

Unfortunately matplotlib 3.1.1 broke seaborn heatmaps; and in general inverted axes with fixed ticks.
This is fixed in the current development version; you may hence

• revert to matplotlib 3.1.0
• use matplotlib 3.1.2 or higher
• set the heatmap limits manually (ax.set_ylim(bottom, top) # set the ylim to bottom, top)