class_docstr: An accumulator object capable of computing NIST score using multiple references.
docstr: Return the NIST informativeness of an n-gram.
docstr_tok: ["Return","the","NIST","informativeness","of","an","n-gram","."]
code: def info(self, ngram):
      """Return the NIST informativeness of an n-gram."""
      if ngram not in self.ref_ngrams[len(ngram)]:
          return 0.0
      return math.log(
          self.ref_ngrams[len(ngram) - 1][ngram[:-1]]
          / float(self.ref_ngrams[len(ngram)][ngram]),
          2,
      )
  
imports: from __future__ import unicode_literals
  from __future__ import division
  from builtins import zip
  from builtins import range
  from past.utils import old_div
  from builtins import object
  from collections import defaultdict
  import math
  import re
label_desc: Use image node_id 5 for calling the NISTScore obj's underlying member method code with example usage: obj.info(ngram) and returns: math, int