colNames
is an internal helper function.colNames(df, slim = TRUE, concatenate = NULL, debug = FALSE)
colNames
takes a data frame as input and return
either column names occuring once or multiple times.
Matching is done by the 'base name' (the substring to the
left of the last period, if any). The return type is a
string vector by default, or a single string of colum names
separated by a string 'concatenate' (see 'collapse' in
paste
for details).