code: def lambert_equal_area_projection_polar(theta, phi):
      r"""Lambert Equal Area Projection from polar sphere to plane
  
      Return positions in (y1,y2) plane corresponding to the points
      with polar coordinates (theta, phi) on the unit sphere, under the
      Lambert Equal Area Projection mapping (see Mardia and Jupp (2000),
      Directional Statistics, p. 161).
  
      See doc for ``sphere2cart`` for angle conventions
  
      - $0 \le \theta \le \pi$ and $0 \le \phi \le 2 \pi$
      - $|(y_1,y_2)| \le 2$
  
      The Lambert EAP maps the upper hemisphere to the planar disc of radius 1
      and the lower hemisphere to the planar annulus between radii 1 and 2,
      and *vice versa*.
  
      Parameters
      ----------
      theta : array_like
         theta spherical coordinates
      phi : array_like
         phi spherical coordinates
  
      Returns
      -------
      y : (N,2) array
         planar coordinates of points following mapping by Lambert's EAP.
      """
  
      return (
          2
          * np.repeat(np.sin(theta / 2), 2).reshape((theta.shape[0], 2))
          * np.column_stack((np.cos(phi), np.sin(phi)))
      )
  
imports: import itertools
  import math
  import numpy
  import numpy.linalg
label_desc: Use image node_id 11 for calling a global function with example usage: lambert_equal_area_projection_polar(theta, phi) and returns: unknown