Combine the terms in two categorical columns to form a new categorical column.
Output: A new categorical column is generated with combined terms.
First selected categorical column, whose values should be concatenated to the second one (default: first categorical column of the matrix). The new generated categorical column contains the two values concatenated with a “_” in between.
Second selected categorical column, whose values should be concatenated to the first one (default: first categorical column of the matrix). The new generated categorical column contains the two values concatenated with a “_” in between.