code: def _entropy(self, *args):
      def integ(x):
          val = self._pdf(x, *args)
          return val * log(val)
  
      entr = -integrate.quad(integ, self.a, self.b)[0]
      if not np.isnan(entr):
          return entr
      else:
          raise ValueError("Problem with integration.  Returned nan.")
  
file_path: statsmodels/statsmodels/sandbox/examples/bayesprior.py
imports: import numpy
  from matplotlib import pyplot
  from scipy import stats, integrate
  from scipy.stats import rv_continuous
  from scipy.special import gammaln, gammaincinv, gammainc
  from numpy import log, exp
label_desc: Use image node_id 6 for calling the igamma_gen obj's underlying member method code with example usage: obj._entropy() and returns: unknown, entr