Remove features from dtm of each group base don cc_test and tsj
select_features(m, indices1, indices2, cc_test = 0.3, tsj = 3)
global dtm
indices of documents of group 1
indices of documents of group 2
maximum contingency coefficient value for the feature to be kept in both groups.
minimum feature frequency in the dtm
a list of two character vectors : cols1
is the name of features to
keep in group 1, cols2
the name of features to keep in group 2
Internal function, not to be used directly