        +Z axis.

               [1,n] = size(lon); double = class(lon)

      lat      the angle of the point measured from the XY plane in radians.
               The angle increases in the direction of the +Z axis.

               [1,n] = size(lat); double = class(lat)

   the call:

      jacobi = <b>cspice_drdlat</b>( r, lon, lat)

   returns:

      jacobi   the matrix of partial derivatives of the conversion between
               latitudinal and rectangular coordinates, evaluated at the input
      