rrspacing(3I)

NAME
     RRSPACING - Returns the reciprocal of the relative spacing of numeric
     model numbers near the argument value

SYNOPSIS
     RRSPACING ([X=]x)

IMPLEMENTATION
     UNICOS, UNICOS/mk, and IRIX systems

STANDARDS
     Fortran 90

DESCRIPTION
     The RRSPACING intrinsic function returns the reciprocal of the
     relative spacing of the numeric real model numbers near the argument
     value.  For more information on the real number model, see the
     MODELS(3I) man page.  It accepts the following argument:

     x    Must be of type real

     RRSPACING is an elemental function.  The name of this intrinsic cannot
     be passed as an argument.

NOTES
     This routine is implemented on CRAY T90 systems that support IEEE
     arithmetic by calls to scalar-only library routines.

RETURN VALUES
     The result type and type parameter are the same as x.  The result has
     the value
     |x multiplied by b**-e | multiplied by b**p, where b, e, and p are
     defined in the real number model.

EXAMPLES
     The following code was run on several systems:

          REAL(KIND=4) r4
          REAL(KIND=8) r8
          REAL(KIND=16) r16
          REAL rd
          r4=-3.0_4
          r8=-3.0_8
          r16=-3.0_16
          rd=-3.0
          PRINT *,'RRSPACING r4=',RRSPACING(r4)
          PRINT *,'RRSPACING r8=',RRSPACING(r8)
          PRINT *,'RRSPACING r16=',RRSPACING(r16)
          PRINT *,'RRSPACING rd=',RRSPACING(rd)
          END

     On a CRAY Y-MP E system, the results were as follows:

          RRSPACING r4= 12582912.
          RRSPACING r8= 105553116266496.
          RRSPACING r16= 2.9710560942849126597578981376E+28
          RRSPACING rd= 105553116266496.

     On an IRIX system, the results were as follows:

          RRSPACING r4= 12582912.
          RRSPACING r8= 6755399441055744.
          RRSPACING r16= 1.216944576219100225436835007716096E+32
          RRSPACING rd= 12582912.

     On a UNICOS/mk system, the results were as follows:

          RRSPACING r4= 12582912.
          RRSPACING r8= 6755399441055744.
          RRSPACING rd= 6755399441055744.

     On a CRAY T90 system that supports IEEE floating-point arithmetic, the
     results were as follows:

          RRSPACING r4= 12582912.
          RRSPACING r8= 6755399441055744.
          RRSPACING r16= 7.788445287802241442795744493830144E+33
          RRSPACING rd= 6755399441055744.

SEE ALSO
     MODELS(3I)

     Intrinsic Procedures Reference Manual, publication SR-2138, for the
     printed version of this man page.