FUNCTION VOID LookUp2 (Three,NCol, TableVal, Arg, Val2, Val3)

/* Interpolate linearly in table 'TableVal',
 *   Find values 'Val2' and 'Val3' corresponding to argument 'Arg'.
 * It is assumed that Arg outside range gives outermost values.
*/

  LANGUAGE F77

  INPUT 
     INT   Three,NCol;
     FLOAT TableVal[NCol,Three], Arg;

  OUTPUT
     FLOAT Val2, Val3;

  EXTERNAL LookUp2 (Three,NCol, TableVal, Arg, Val2, Val3)

  EXTENSIONS
    JACOBIAN LOOKUP2J;
    JACOBIAN_OVER Val2, Val3;
    JACOBIAN_UNDER Arg;
  END_EXTENSIONS

  END_FUNCTION