Source code for pygsp.graphs.gutils

# -*- coding: utf-8 -*-

from pygsp import utils

import numpy as np
import scipy as sp
from scipy import sparse
from math import isinf, isnan

logger = utils.build_logger(__name__)

[docs]def check_weights(W): r""" Check the characteristics of the weights matrix. Parameters ---------- W : weights matrix The weights matrix to check Returns ------- A dict of bools containing informations about the matrix has_inf_val : bool True if the matrix has infinite values else false has_nan_value : bool True if the matrix has a not a number value else false is_not_square : bool True if the matrix is not square else false diag_is_not_zero : bool True if the matrix diagonal has not only zero value else false Examples -------- >>> from scipy import sparse >>> from pygsp.graphs import gutils >>> np.random.seed(42) >>> W = sparse.rand(10,10,0.2) >>> weights_chara = gutils.check_weights(W) """ has_inf_val = False diag_is_not_zero = False is_not_square = False has_nan_value = False if isinf(W.sum()): logger.warning("GSP_TEST_WEIGHTS: There is an infinite " "value in the weight matrix") has_inf_val = True if abs(W.diagonal()).sum() != 0: logger.warning("GSP_TEST_WEIGHTS: The main diagonal of " "the weight matrix is not 0!") diag_is_not_zero = True if W.get_shape()[0] != W.get_shape()[1]: logger.warning("GSP_TEST_WEIGHTS: The weight matrix is " "not square!") is_not_square = True if isnan(W.sum()): logger.warning("GSP_TEST_WEIGHTS: There is an NaN " "value in the weight matrix") has_nan_value = True return {'has_inf_val': has_inf_val, 'has_nan_value': has_nan_value, 'is_not_square': is_not_square, 'diag_is_not_zero': diag_is_not_zero}