code: def ra_dec_to_xyz(ra, dec):
      """Convert ra & dec to Euclidean points
  
      Parameters
      ----------
      ra, dec : ndarrays
  
      Returns
      x, y, z : ndarrays
      """
      sin_ra = np.sin(ra * np.pi / 180.0)
      cos_ra = np.cos(ra * np.pi / 180.0)
  
      sin_dec = np.sin(np.pi / 2 - dec * np.pi / 180.0)
      cos_dec = np.cos(np.pi / 2 - dec * np.pi / 180.0)
  
      return (cos_ra * sin_dec, sin_ra * sin_dec, cos_dec)
  
file_path: astroML/astroML/correlation.py
imports: import numpy
  from sklearn.neighbors import KDTree
  from sklearn.utils import check_random_state
label_desc: Use image node_id 2 for calling a global function with example usage: ra_dec_to_xyz(ra, dec) and returns: unknown,  unknown,  cos_dec