UNIQUE_WORDS - detects all distinct elements of a cell array of
chars (used by tmg.m, tmg_query.m, tdm_update.m)
[NEW_WORDS, NEW_DOC_IDS]=UNIQUE_WORDS(WORDS, DOC_IDS, N_DOCS)
returns in NEW_WORDS all distinct elements of the cell array
of chars WORDS. DOC_IDS is the vector of the document identifiers
containing the corresponding words, while N_DOCS is the total
number of documents contained to the collection. NEW_DOC_IDS
contains the inverted index of the collection as a cell array
of 2 x N_DOCS arrays.
Copyright 2011 Dimitrios Zeimpekis, Eugenia Maria Kontopoulou,
Efstratios Gallopoulos