code: def drdlat(r, lon, lat):
      
      r = ctypes.c_double(r)
      lon = ctypes.c_double(lon)
      lat = ctypes.c_double(lat)
      jacobi = stypes.emptyDoubleMatrix()
      libspice.drdlat_c(r, lon, lat, jacobi)
      return stypes.cMatrixToNumpy(jacobi)
docs: Compute the Jacobian of the transformation from latitudinal to
      rectangular coordinates.
  
      http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/drdlat_c.html
  
      :param r: Distance of a point from the origin.
      :type r: float
      :param lon: Angle of the point from the XZ plane in radians.
      :type lon: float
      :param lat: Angle of the point from the XY plane in radians.
      :type lat: float
      :return: Matrix of partial derivatives.
      :rtype: 3x3-Element Array of floats