docstr: Return a parametric approximation of the z-score associated
  with the null hypothesis: (H0) 'contrast equals baseline'
docstr_tok: ["Return","a","parametric","approximation","of","the","z-score","associated","with","the","null","hypothesis",":","(","H0",")","'contrast","equals","baseline","'"]
code: def zscore(self, baseline=0.0):
      """
      Return a parametric approximation of the z-score associated
      with the null hypothesis: (H0) 'contrast equals baseline'
      """
      if self._pvalue is None or self._baseline != baseline:
          self._pvalue = self.pvalue(baseline)
  
      # Avoid inf values kindly supplied by scipy.
      z = zscore(self._pvalue)
      return z
  
imports: import numpy
  import scipy.stats
  from nipy.algorithms.statistics.utils import z_score
  from ..utils import mahalanobis
  from .None import kalman
label_desc: Use image node_id 5 for calling the contrast obj's underlying member method code with example usage: obj.zscore(baseline) and returns: z