code: def crystalball_pdf(x, b, m):
      if x > -b:
          return math.exp(-0.5 * x * x)
      return math.exp(
          m * math.log(m / b)
          - 0.5 * b * b
          - m * math.log(m / b - b - x)
      )
  
imports: import math
  import numbers
  import numpy
  from scipy import stats
  from scipy import special
  from ._qmc import check_random_state, Halton, QMCEngine
  from ._unuran.unuran_wrapper import NumericalInversePolynomial
  from scipy._lib._util import check_random_state
label_desc: Use image node_id 14 for calling a global function with example usage: crystalball_pdf(x, b, m) and returns: math, math