code: def lognormal(x, amplitude=1.0, center=0.0, sigma=1):
      """Return a log-normal function.
  
      lognormal(x, amplitude, center, sigma) =
          (amplitude/(x*sigma*s2pi)) * exp(-(ln(x) - center)**2/ (2* sigma**2))
  
      """
      if isinstance(x, (int, float)):
          x = max(tiny, x)
      else:
          x[where(x <= tiny)] = tiny
      return (amplitude / (x * max(tiny, sigma * s2pi))) * exp(
          -((log(x) - center) ** 2) / max(tiny, (2 * sigma**2))
      )
  
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 15 for calling a global function with example usage: lognormal(x, amplitude, center, sigma) and returns: unknown