Changes in version 0.2.10 (2026-05-08) - Fixed failing check on CRAN. Changes in version 0.2.9 (2024-12-14) - Updated maintainer email. - rs_pairs() gets a new argument match_first to control if products in the first period match to themselves (#1). Changes in version 0.2.8 (2023-11-19) - Added a vignette. - rs_matrix() is about twice as fast now. Changes in version 0.2.6 (2023-06-01) - Updated to work with Matrix >= 1.5-0. Changes in version 0.2.3 (2022-03-15) - Making the "Y" vector with rs_matrix() no longer gives an error with length-0 inputs and a factor with non-empty levels. - rs_matrix() cleans up the enclosing environment of its result. Changes in version 0.2.1 (2022-02-13) - rs_pairs() and rs_matrix() are now faster, and less picky about their inputs for time periods. Changes in version 0.2.0 (2021-10-08) - rs_pairs() has been reworked to be much faster and more general, while rs_unpair() has been removed. These changes are not backwards compatible. - Added French translations. - Fixed the NOTE about LazyData from CRAN.