dichotomize: Create dummy columns from logicals or factors in a data frame
Description
This function is deprecated because partition() is more general and
can be used to create dummy columns as well.
Create dummy logical columns from selected columns of the data frame.
Dummy columns may be created for logical or factor columns as follows:
for logical column col, a pair of columns is created named col=T
and col=F where the former (resp. latter) is equal to the original
(resp. negation of the original);
for factor column col, a new logical column is created for each
level l of the factor col and named as col=l with a value set
to TRUE wherever the original column is equal to l.