code: def pearson7(x, amplitude=1.0, center=0.0, sigma=1.0, expon=1.0):
      """Return a Pearson7 lineshape.
  
      Using the Wikipedia definition:
  
      pearson7(x, center, sigma, expon) =
          amplitude*(1+arg**2)**(-expon)/(sigma*beta(expon-0.5, 0.5))
  
      where ``arg = (x-center)/sigma`` and `beta` is the beta function.
  
      """
      expon = max(tiny, expon)
      arg = (x - center) / max(tiny, sigma)
      scale = (
          amplitude
          * gamfcn(expon)
          / (gamfcn(0.5) * gamfcn(expon - 0.5))
      )
      return scale * (1 + arg**2) ** (-expon) / max(tiny, sigma)
  
imports: from numpy import arctan, copysign, cos, exp, isclose, isnan, log, log1p, maximum, minimum, pi, real, sin, sqrt, where
  from scipy.special import betaln
  from scipy.special import erf, erfc
  from scipy.special import gamma
  from scipy.special import loggamma
  from scipy.special import wofz
label_desc: Use image node_id 10 for calling a global function with example usage: pearson7(x, amplitude, center, sigma, expon) and returns: unknown