classification_metrics
                        Calculate binary classification metrics
cosine_similarity       Compute cosine similarity
document_term_matrix    Construct a document-term matrix
extract_html_dir        Extract text from a directory of HTML files
extract_html_text       Extract readable text from HTML
extract_keywords        Extract top TF-IDF keywords
f_measure               F-measure
fit_naive_bayes         Fit a multinomial Naive Bayes text classifier
preprocess_text         Normalize text for document-term analysis
read_label_file         Read a one-label-per-line file
split_sentences         Split text into sentences
stratified_folds        Create stratified cross-validation folds
tf_idf                  Calculate TF-IDF weights
