docstr: evaluates Goldstein-Price's function for a list of coeffs
  
  f(x) = (1 + (x_0 + x_1 + 1)^2 * f_0(x)) * (30 + (2*x_0 - 3*x_1)^2 * f_1(x))
  
  Where:
  f_0(x) = 19 - 14*x_0 + 3*x_(0)^2 - 14*x_1 + 6*x_(0)*x_(1) + 3*x_(1)^2
  and
  f_1(x) = 18 - 32*x_0 + 12*x_(0)^2 + 48*x_1 - 36*x_(0)*x_(1) + 27*x_(1)^2
  
  Inspect with mystic_model_plotter using::
      mystic.models.goldstein -b "-5:5:.1, -5:5:.1" -d -x 1
  
  The minimum is f(x)=3.0 at x=(0,-1)
code: def function(self, coeffs):
      r"""evaluates Goldstein-Price's function for a list of coeffs
  
      f(x) = (1 + (x_0 + x_1 + 1)^2 * f_0(x)) * (30 + (2*x_0 - 3*x_1)^2 * f_1(x))
  
      Where:
      f_0(x) = 19 - 14*x_0 + 3*x_(0)^2 - 14*x_1 + 6*x_(0)*x_(1) + 3*x_(1)^2
      and
      f_1(x) = 18 - 32*x_0 + 12*x_(0)^2 + 48*x_1 - 36*x_(0)*x_(1) + 27*x_(1)^2
  
      Inspect with mystic_model_plotter using::
          mystic.models.goldstein -b "-5:5:.1, -5:5:.1" -d -x 1
  
      The minimum is f(x)=3.0 at x=(0,-1)"""
      x0, x1 = coeffs
      f0 = (
          19
          - 14 * x0
          + 3 * x0**2
          - 14 * x1
          + 6 * x0 * x1
          + 3 * x1**2
      )
      f1 = (
          18
          - 32 * x0
          + 12 * x0**2
          + 48 * x1
          - 36 * x0 * x1
          + 27 * x1**2
      )
      return (1 + (x0 + x1 + 1) ** 2 * f0) * (
          30 + (2 * x0 - 3 * x1) ** 2 * f1
      )
  
imports: from .abstract_model import AbstractFunction
  from math import sin, cos, sqrt, pi, exp
label_desc: Use image node_id 2 for calling the GoldsteinPrice obj's underlying member method code with example usage: obj.function(coeffs) and returns: unknown