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The matrix multiply operator ‘%*%’ is now an S3 generic, belonging to new group generic ‘matrixOps’. From Tomasz Kalinowski's contribution in PR#18483.
New function ‘array2DF()’ to convert arrays to data frames, particularly useful for the list arrays created by ‘tapply()’.
The performance of ‘df[j] <- value’ (including for missing ‘j’) and ‘write.table(df)’ has been improved for data frames ‘df’ with a large number of columns. (Thanks to Gabriel Becker's PR#18500, PR#18503 and discussants, prompted by a report from Toby Dylan Hocking on the R-devel mailing list.)
New generic ‘.AtNames()’ added to enable class-specific completions after ‘@’. The formerly internal function ‘findMatches()’ is now exported, mainly for use in methods for ‘.DollarNames()’ and ‘.AtNames()’.