Procedure

     NECHR (Not Equivalent characters)

     ENTRY NECHR ( A, B )

Abstract

     Return .TRUE. if two given characters are not equivalent if the
     case of the characters is ignored.

Required_Reading

     None.

Keywords

     CHARACTER

Declarations

    IMPLICIT NONE

    CHARACTER*(1)         A
    CHARACTER*(1)         B

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     A          I   one of the characters to check
     B          I   the other character to check

     The function returns .TRUE. if the characters are not equivalent

Detailed_Input

     A,
     B        are two characters that are to be compared to see
              if they are different letters. Letters that have
              the same value when converted to uppercase are
              considered to be equivalent.

Detailed_Output

     The function returns the value .FALSE. if the two input characters
     are the same or can be made the same by converting both to
     upper or lower case. Otherwise it returns .TRUE.

Parameters

     None.

Exceptions

     Error free.

Files

     None.

Particulars

     This routine simply determines the truth value of .NOT. EQCHR.
     See the entry point EQCHR for a discussion of that function.

Examples

     Suppose you want to determine whether or not two strings
     are the same up to differences in case. The following
     code fragment shows how you can use this routine to check
     for the equivalence of character strings.

        MORE  = .TRUE.
        SAME  = .TRUE.
        L1    =  LEN(STR1)
        L2    =  LEN(STR2)
        CHECK = MIN ( L1, L2 )

        DO WHILE ( SAME .AND. MORE )

           IF ( NECHR(STR1(I:I),STR2(I:I) ) THEN
              SAME = .FALSE.
           END IF

           I    = I + 1
           MORE = I .LT. CHECK

        END DO

        IF ( .NOT. SAME ) THEN

           There's nothing to do, we already know the strings
           are not the same.

        ELSE IF ( L1 .LT. L2 ) THEN

           The only way the strings can be regarded as being equal
           is if the extra unchecked characters in STR2 are all blank.

           SAME = STR2(I:) .EQ. ' '

        ELSE

           Same test as previous one but with STR1 this time.

           SAME = STR1(I:) .EQ. ' '

        END IF

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

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

Version

    SPICELIB Version 1.0.1, 26-OCT-2021 (JDR)

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.0, 17-SEP-1998 (EDW)

        Replace the UVALUE data statement with a loop to fill
        UVALUE. The Absoft Mac compiler failed to compile the
        data statement correctly, and so this function failed
        to work properly in all situations on the Mac. The
        corrects the problem and functions on all platforms.

    SPICELIB Version 1.0.0, 16-MAY-1995 (WLT)