ieee_unordered(3I)

NAME
     IEEE_UNORDERED - Tests for x or y being a NaN

SYNOPSIS
     IEEE_UNORDERED ([X=]x, [Y=]y)

IMPLEMENTATION
     UNICOS/mk and IRIX systems

     CRAY T90 systems that support IEEE floating-point arithmetic

STANDARDS
     CF90 and MIPSpro 7 Fortran 90 compiler extension to Fortran 90

     IEEE Standard for Binary Floating-point Arithmetic

DESCRIPTION
     The IEEE_UNORDERED intrinsic function tests for x or y being a NaN.
     It accepts the following arguments:

     x         Must be of type real.  Can be a scalar or an array.

     y         Must be of type real.  y must be conformable with x.

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

NOTES
     The IEEE intrinsic procedures use the named constants contained in a
     system module, so you must include one of the following statements in
     your program:

     * On UNICOS and UNICOS/mk systems:  USE CRI_IEEE_DEFINITIONS

     * On UNICOS, UNICOS/mk, and IRIX systems:  USE FTN_IEEE_DEFINITIONS

     The CRI_IEEE_DEFINITIONS module is obsolescent.  It will be removed
     for the CF90 4.0 release.

RETURN VALUES
     The result type and type parameter are default logical.  If either x
     or y is an array, the result is an array of the same shape as one of
     the array arguments.

     The return value is .TRUE. if either x or y is a NaN, otherwise the
     return value is .FALSE..  The operation does not raise the Invalid
     Operation interrupt.

     If x and y are both scalar, the result is a scalar.

     If x is an array and y is scalar, the result is an array in which each
     element has the value .TRUE. or .FALSE., depending on whether x
                                                                    i
     is unordered with y.

     If x is scalar and y is an array, the result is an array in which each
     element has the value .TRUE. or .FALSE., depending on whether x is
     unordered with y .
                     i

     If x is an array and y is an array, the result is an array in which
     each element has the value .TRUE. or .FALSE., depending on whether
     x  is unordered with y .
      i                    i

EXAMPLES
          REAL   x,y
          ...                       ! Compute X.
          IF (IEEE_UNORDERED(x, y)) THEN
             ...                    ! Do something.
          ELSE
             ...                    ! Do something else.
          END IF

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