class_docstr: Statistics for binary decision,
  including precision, recall, false positive, false negative
code: def precision(self):
      if self.nr_pred_pos == 0:
          return 0
      return self.corr_pos * 1.0 / self.nr_pred_pos
  
imports: import numpy
label_desc: Use image node_id 4 for calling the BinaryStatistics obj's underlying member method code with example usage: obj.precision() and returns: unknown, int