IEEE_IS_NAN(3I) Last changed: 1-6-98
NAME
IEEE_IS_NAN - Tests for x being a NaN
SYNOPSIS
IEEE_IS_NAN ([X=]x)
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_IS_NAN intrinsic function returns the value TRUE if x is a
NaN and return the value FALSE otherwise.
This function accepts the following argument:
x Must be of type real.
IEEE_IS_NAN 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 of type default logical. If x
is an array, the result is an array of the same shape as x.
The value returned has the value TRUE if x is a NaN and the value
FALSE otherwise.
EXAMPLES
REAL x
... ! Compute X.
IF (IEEE_IS_NAN(x)) 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.
