PR Summary

Taking pcolormesh(x, y, Z), in 3.3.0 (#16258) we introduced the 'nearest' and 'auto' kwargs for shading in pcolor(mesh) to properly allow for not dropping the last row and column in the case that cell centres are passed for x and y.

In 3.3:

• Default: 'flat'
• Cell edges: Z.shape = M, N, len(x) = N+1, len(y) = M+1
  • 'flat': x and y specify cell edges
  • 'nearest'/'gouraud': TypeError
  • 'auto': 'flat'
• Cell centers: Z.shape = M, N, len(x) = N, len(y) = M
  • 'flat': DeprecationWarning and drop last row and column
  • 'nearest'/'gouraud': x and y specify cell centers
  • 'auto': 'nearest'

In 3.5:

• Default: 'auto'
• Cell edges: Z.shape = M, N, len(x) = N+1, len(y) = M+1
  • 'flat': x and y specify cell edges
  • 'nearest'/'gouraud': TypeError
  • 'auto': 'flat'
• Cell centers: Z.shape = M, N, len(x) = N, len(y) = M
  • 'flat': TypeError
  • 'nearest'/'gouraud': x and y specify cell centers
  • 'auto': 'nearest'

PR Checklist

• Has pytest style unit tests (and pytest passes).
• Is Flake 8 compliant (run flake8 on changed files to check).
• New features are documented, with examples if plot related.
• Documentation is sphinx and numpydoc compliant (the docs should build without error).
• Conforms to Matplotlib style conventions (install flake8-docstrings and run flake8 --docstring-convention=all).
• New features have an entry in doc/users/next_whats_new/ (follow instructions in README.rst there).
• API changes documented in doc/api/next_api_changes/ (follow instructions in README.rst there).