Cross-tabulates columns of a dataframe into a matrix with NAs for unspecified pairs
df_xtab_matrix(model, df, rows, columns)
A cross-tabulated matrix matrix with NAs for unspecified pairs.
A formula
indicating relevant columns from data frame
A data.frame
of columns to cross-tabulate
A vector
of row names for the matrix to sort by
A vector
of column names for the matrix to sort by