DEP: stats.ttest_ind: deprecate `random_state`/`permutation`; require keywords for most args

Contributor & Development Discussion scipy
1

Hi Team,

The permutation and random_state arguments of ttest_ind were added in gh-4824 to enable the user to perform a permutation version of the t-test. A standard API for performing resampling versions of tests using a method argument was developed in gh-18227. SPEC 7 deprecation of random_state arguments throughout the package (gh-21833) provides additional impetus for transitioning from random_state to method.

gh-21921 would make the following changes to ttest_ind:

  • adds a method argument that allows the user to configure permutation and Monte Carlo versions of the test.
  • deprecates permutation and random_state arguments in favor of method.
  • deprecates positional use of all arguments of ttest_ind after x and y. The removal of permutation and random_state would also require later arguments (alternative and trim) to be passed by keyword, anyway, and keyword-only is the modern preference for optional parameters, so the thought is that we’d make all the optional parameters keyword-only at the same time.

Thoughts on this? Please join the discussion in gh-21921!

Matt