class_docstr: This class enables the extraction of image features (Harilick
  features) and basic statistics over a segmentation
class_docstr_tok: ["This","class","enables","the","extraction","of","image","features","(","Harilick","features",")","and","basic","statistics","over","a","segmentation"]
docstr: Calculates the entropy over the glcm matrix
  
  :param matrix:
  :return:
docstr_tok: ["Calculates","the","entropy","over","the","glcm","matrix",":","param","matrix",":",":","return",":"]
code: def entropy(self, matrix):
      """
      Calculates the entropy over the glcm matrix
  
      :param matrix:
      :return:
      """
      entropy = 0
      for i in range(0, matrix.shape[0]):
          for j in range(0, matrix.shape[0]):
              if matrix[i, j] > 0:
                  entropy += matrix[i, j] * math.log(matrix[i, j])
      return entropy
  
imports: from __future__ import absolute_import, print_function, division
  import numpy
  import numpy.ma
  import math
  import scipy.stats.mstats
  import scipy.ndimage
  from niftynet.utilities.util_common import MorphologyOps, CacheFunctionOutput
label_desc: Use image node_id 26 for calling the RegionProperties obj's underlying member method code with example usage: obj.entropy(matrix) and returns: entropy