A function to calculate a number of information-theoretic measures on terms in a contingency table, including point-wise mutual information.
pmi(contingency_table, display_top_x_terms = 20, term_threshold = 5,
every_category_counts = FALSE)A contingency table generated by the `contingency_table()` function.
Defaults to 20, the number of top ranked terms to display for each measure.
The threshold at which terms are eliminated from the contingency table for the purposes of calculating information-theoretic quantities. THis gets around issues with terms that only appear once having very high PMI.
Defaults to FALSE, if TRUE, then terms are removed if they do not appear at least term_threshold times in every row (category) of the contingency table.
A list object containing lots of different information theoretic measures calculated on the contingency table. If a sparse matrix was provided, then a sparse PMI table is returned. Note that the "zero" entries in this sparse matrix are actually -Inf, but cannot be represented as such using the slam sparse matrix libraries (which this package does), so you will manually need to replace the zero entries with -Inf if you want to compare to a dense matrix.