Procedure

     TOUCHD ( Touch a variable )

     DOUBLE PRECISION FUNCTION TOUCHD ( DP )

Abstract

     Return the value of a double precision number.

Required_Reading

     None.

Keywords

     UTILITY

Declarations

     IMPLICIT NONE

     DOUBLE PRECISION      DP

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     DP        I   any double precision number

      The function returns the value of DP.

Detailed_Input

     DP       is any double precision number

Detailed_Output

     The function returns the input d.p.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     This is a utility routine so that formal arguments to a routine
     that are never used can be given the appearance of being used
     to a compiler. In this way it is possible to leave "hooks" in
     a calling sequence even if those variables are for the moment
     unused. Similarly, variables declared for future use can be left
     in place so that they don't need to be commented out

Examples

     Suppose that a routine takes as an argument a
     fortran structure implemented as a set of parallel arrays.
     But that one of the arrays is not needed for the purposes of
     the routine. This routine allows you to touch that array
     without changing it.


        SUBROUTINE INCPTR ( N, PTR, VALUES )

        This routine increments the current pointer into a circular
        array of double precision numbers.

        INTEGER               N
        INTEGER               PTR
        DOUBLE PRECISION      VALUES ( * )

        Even though we don't need to do anything with the values
        array, it's passed for the sake of uniformity in calling
        sequences. Touch the VALUES array so that the compiler
        will think it's been used.

        VALUES(1) = TOUCHD ( VALUES(1) )

        PTR = PTR + 1

        IF ( PTR .GT. N ) THEN
           PTR = 1
        END IF
        RETURN

Restrictions

     1)  If you use this routine, it would be a very good idea to
         write down why you are using it in the calling routine.

Literature_References

     None.

Author_and_Institution

     J. Diaz del Rio    (ODC Space)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.0.1, 16-AUG-2021 (JDR)

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.0, 06-MAY-1994 (WLT)