This function copied directly from plyr, and modified to use a different name to avoid namespace collisions with dplyr/tidyverse functions.
mutate_plyr(.data, ...)
the data frame to transform
named parameters giving definitions of new columns.
This function is very similar to transform
but it executes
the transformations iteratively so that later transformations can use the
columns created by earlier transformations. Like transform, unnamed
components are silently dropped.
Mutate seems to be considerably faster than transform for large data frames.