class_docstr: Abstract class for confusion matrix
  
  You shouldn't instantiate this class.
  You might instantiate ConfusionMatrix or BinaryConfusionMatrix classes
class_docstr_tok: ["Abstract","class","for","confusion","matrix","You","should","n't","instantiate","this","class",".","You","might","instantiate","ConfusionMatrix","or","BinaryConfusionMatrix","classes"]
docstr: Returns sum of a confusion matrix.
  Also called "population"
  It should be the number of elements of either y_true or y_pred
docstr_tok: ["Returns","sum","of","a","confusion","matrix",".","Also","called","``","population","''","It","should","be","the","number","of","elements","of","either","y_true","or","y_pred"]
code: def sum(self):
      """
      Returns sum of a confusion matrix.
      Also called "population"
      It should be the number of elements of either y_true or y_pred
      """
      return self.to_dataframe().sum().sum()
  
imports: import numpy
  import pandas
  import collections
  import pandas_ml
  from pandas_ml.confusion_matrix.stats import binom_interval, class_agreement, prop_test
label_desc: Use image node_id 13 for calling the ConfusionMatrixAbstract obj's underlying member method code with example usage: obj.sum() and returns: self