code: def rectangle(
      x,
      amplitude=1.0,
      center1=0.0,
      sigma1=1.0,
      center2=1.0,
      sigma2=1.0,
      form="linear",
  ):
      """Return a rectangle function: step up, step down.
  
      Starts at 0.0, rises to `amplitude` (at `center1` with width `sigma1`),
      then drops to 0.0 (at `center2` with width `sigma2`) with `form`:
      - `'linear'` (default) = ramp_up + ramp_down
      - `'atan'`, `'arctan`' = amplitude*(atan(arg1) + atan(arg2))/pi
      - `'erf'`              = amplitude*(erf(arg1) + erf(arg2))/2.
      - `'logisitic'`        = amplitude*[1 - 1/(1 + exp(arg1)) - 1/(1+exp(arg2))]
  
      where ``arg1 = (x - center1)/sigma1`` and
      ``arg2 = -(x - center2)/sigma2``.
  
      See Also
      --------
      step
  
      """
      arg1 = (x - center1) / max(tiny, sigma1)
      arg2 = (center2 - x) / max(tiny, sigma2)
  
      if form == "erf":
          out = 0.5 * (erf(arg1) + erf(arg2))
      elif form == "logistic":
          out = 1.0 - 1.0 / (1.0 + exp(arg1)) - 1.0 / (1.0 + exp(arg2))
      elif form in ("atan", "arctan"):
          out = (arctan(arg1) + arctan(arg2)) / pi
      elif form == "linear":
          out = 0.5 * (
              minimum(1, maximum(-1, arg1))
              + minimum(1, maximum(-1, arg2))
          )
      else:
          msg = (
              f"Invalid value ('{form}') for argument 'form'; should be one "
              "of 'erf', 'logistic', 'atan', 'arctan', or 'linear'."
          )
          raise ValueError(msg)
  
      return amplitude * out
  
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 25 for calling a global function with example usage: rectangle(x, amplitude, center1, sigma1, center2, sigma2, form) and returns: unknown