- Character values with "\n" are not supported.
- The R apply function operates only on matrices and not data frames. If the input to the R apply function is a data frame, the function tries to convert the data frame to a matrix using the as.matrix function.
Because matrices cannot contain mixed data types, the as.matrix function converts numeric columns to strings and creates a matrix of strings. As a result, R functions must not be used on mixed type data frames.
Users must project out the columns in the tadf argument of the aa.apply function so that all input columns are either numeric or character.