BagOfWordsData.py 文件源码

def getWordTypeCooccurPieces(self, dtype=np.float32):
        """ Calculate building blocks for word-word cooccur calculation

        These pieces can be used for incremental construction.

        Returns
        -------
        Q : 2D matrix, W x W (where W is vocab_size)
        sameWordVec : 1D array, size W
        nDoc : scalar
        """
        sameWordVec = np.zeros(self.vocab_size)
        data = np.zeros(self.word_count.shape, dtype=dtype)

        for docID in xrange(self.nDoc):
            start = self.doc_range[docID]
            stop = self.doc_range[docID + 1]
            N = self.word_count[start:stop].sum()
            NNm1 = N * (N - 1)
            sameWordVec[self.word_id[start:stop]] += \
                self.word_count[start:stop] / NNm1
            data[start:stop] = self.word_count[start:stop] / np.sqrt(NNm1)

        # Now, create a sparse matrix that's D x V
        sparseDocWordMat = scipy.sparse.csr_matrix(
            (data, self.word_id, self.doc_range),
            shape=(self.nDoc, self.vocab_size),
            dtype=dtype)
        # Q : V x V
        from sklearn.utils.extmath import safe_sparse_dot
        Q = safe_sparse_dot(
            sparseDocWordMat.T, sparseDocWordMat, dense_output=1)
        return Q, sameWordVec, self.nDoc