*
* string_arg.F
*


      SUBROUTINE string_arg_init(id)

      INCLUDE 'ferret_cmn/EF_Util.cmn'

      INTEGER id, arg

      CALL ef_set_desc(id,'sets result equal to input' )

      CALL ef_set_num_args(id, 2)
      CALL ef_set_axis_inheritance(id, IMPLIED_BY_ARGS, 
     .     IMPLIED_BY_ARGS, IMPLIED_BY_ARGS, IMPLIED_BY_ARGS)
      CALL ef_set_piecemeal_ok(id, NO, NO, NO, NO)

      arg = 1
      CALL ef_set_arg_name(id, arg, 'A')
      CALL ef_set_arg_unit(id, arg, ' ')
      CALL ef_set_arg_desc(id, arg, 'this arg is passed through')
      CALL ef_set_axis_influence(id, arg, YES, YES, YES, YES)

      arg = 2
      CALL ef_set_arg_type(id, arg, STRING_ARG)
      CALL ef_set_arg_name(id, arg, 'string')
      CALL ef_set_arg_unit(id, arg, ' ')
      CALL ef_set_axis_influence(id, arg, NO, NO, NO, NO)


      RETURN 
      END


*
* In this subroutine we compute the result
*
      SUBROUTINE string_arg_compute(id, arg_1, arg_2, result)

      INCLUDE 'ferret_cmn/EF_Util.cmn'
      INCLUDE 'ferret_cmn/EF_mem_subsc.cmn'

      INTEGER id

      REAL bad_flag(1:EF_MAX_ARGS), bad_flag_result

      REAL arg_1(mem1lox:mem1hix, mem1loy:mem1hiy, 
     .           mem1loz:mem1hiz, mem1lot:mem1hit)
      REAL arg_2(mem2lox:mem2hix, mem2loy:mem2hiy, 
     .           mem2loz:mem2hiz, mem2lot:mem2hit)
      REAL result(memreslox:memreshix, memresloy:memreshiy,
     .            memresloz:memreshiz, memreslot:memreshit)

* After initialization, the 'res_' arrays contain indexing information 
* for the result axes.  The 'arg_' arrays will contain the indexing 
* information for each variable's axes. 

      INTEGER res_lo_ss(4), res_hi_ss(4), res_incr(4)
      INTEGER arg_lo_ss(4,1:EF_MAX_ARGS), arg_hi_ss(4,1:EF_MAX_ARGS),
     .     arg_incr(4,1:EF_MAX_ARGS)

      CHARACTER arg_value*128
      INTEGER arg, i, j, k, l, i1, j1, k1, l1

      arg = 2
      CALL ef_get_arg_string(id, arg, arg_value)
      print *, ' string argument ' 
      print *, arg_value


      CALL ef_get_res_subscripts(id, res_lo_ss, res_hi_ss, res_incr)
      CALL ef_get_arg_subscripts(id, arg_lo_ss, arg_hi_ss, arg_incr)
      CALL ef_get_bad_flags(id, bad_flag, bad_flag_result)

      i1 = arg_lo_ss(X_AXIS,ARG1)
      DO 400 i=res_lo_ss(X_AXIS), res_hi_ss(X_AXIS)

         j1 = arg_lo_ss(Y_AXIS,ARG1)
         DO 300 j=res_lo_ss(Y_AXIS), res_hi_ss(Y_AXIS)

            k1 = arg_lo_ss(Z_AXIS,ARG1)
            DO 200 k=res_lo_ss(Z_AXIS), res_hi_ss(Z_AXIS)

               l1 = arg_lo_ss(T_AXIS,ARG1)
               DO 100 l=res_lo_ss(T_AXIS), res_hi_ss(T_AXIS)

                  IF ( arg_1(i,j,k,l) .EQ. bad_flag(1) ) THEN

                     result(i,j,k,l) = bad_flag_result

                  ELSE

                     result(i,j,k,l) = arg_1(i,j,k,l)

                  END IF

                  l1 = l1 + arg_incr(T_AXIS,ARG1)
 100           CONTINUE

               k1 = k1 + arg_incr(Z_AXIS,ARG1)
 200        CONTINUE

            j1 = j1 + arg_incr(Y_AXIS,ARG1)
 300     CONTINUE

         i1 = i1 + arg_incr(X_AXIS,ARG1)
 400  CONTINUE
      

      RETURN 
      END