code: def normal2d(X, Y, sigx=1.0, sigy=1.0, mux=0.0, muy=0.0):
      z = (X - mux) ** 2 / sigx**2 + (Y - muy) ** 2 / sigy**2
      return np.exp(-z / 2) / (2 * np.pi * sigx * sigy)
  
imports: import numpy
  from bokeh.models import LogColorMapper
  from bokeh.plotting import figure, show
label_desc: Use image node_id 1 for calling a global function with example usage: normal2d(X, Y, sigx, sigy, mux, muy) and returns: unknown