character string containing a regular expression
(or character string for fixed = TRUE) to be matched in the given
character vector (separate multiple column names by | in reg.exp).
ignore.case
logical TRUE to ignore case in matching.
fixed
logical TRUE if columns is a string to be matched as is.
debug
logical indicating printing debug information.
Value
data.frame.
Details
Takes a data frame as input and return it after converting known numeric
columns to numeric.