Procedure

     EXACT ( Round to exact value )

     DOUBLE PRECISION FUNCTION EXACT ( NUMBER, VALUE, TOL )

Abstract

     Round an input double precision number to a specified exact value
     if the number and the value are equal to within some tolerance.

Required_Reading

     None.

Keywords

     COMPARE
     NUMBERS

Declarations

     IMPLICIT NONE

     DOUBLE PRECISION      NUMBER
     DOUBLE PRECISION      VALUE
     DOUBLE PRECISION      TOL

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     NUMBER     I   Double precision number.
     VALUE      I   Target value.
     TOL        I   Tolerance.

     The function returns VALUE whenever |NUMBER - VALUE| < TOL.
                                                          -

Detailed_Input

     NUMBER   is an arbitrary double precision number.

     VALUE    is a target value.

     TOL      is a tolerance. NUMBER and VALUE are considered to
              be equal if they differ by no more than this amount.
              If TOL is negative, they are never considered equal.

Detailed_Output

     The function returns VALUE whenever |NUMBER - VALUE| < TOL, and
     otherwise returns NUMBER.                            -

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     None.

Examples

     C
     C     If the eccentricity is near one, make this a parabola.
     C
           ECC = EXACT ( ECC, 1.D0, 10.D-12 )

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

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

Version

    SPICELIB Version 1.1.0, 12-AUG-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.0, 31-JAN-1990 (IMU)