DNGR.py 文件源码

def PPMI_matrix(M):

    M = scale_sim_mat(M)
    nm_nodes = len(M)

    col_s = np.sum(M, axis=0).reshape(1,nm_nodes)
    row_s = np.sum(M, axis=1).reshape(nm_nodes,1)
    D = np.sum(col_s)
    rowcol_s = np.dot(row_s,col_s)
    PPMI = np.log(np.divide(D*M,rowcol_s))
    PPMI[np.isnan(PPMI)] = 0.0
    PPMI[np.isinf(PPMI)] = 0.0
    PPMI[np.isneginf(PPMI)] = 0.0
    PPMI[PPMI<0] = 0.0

    return PPMI