Excuse me for being basic, but I want to use the 'coherence' function I found on this link to evaluate my latent dirichlet allocation topics and it isn't working with text2vec and I can't tell which library it is in, if it isn't that one.
coherence(x, tcm, metrics = c("mean_logratio", "mean_pmi", "mean_npmi",
"mean_difference", "mean_npmi_cosim", "mean_npmi_cosim2"), smooth = 1e-12,
n_doc_tcm = -1)