ieee_is_finite

Date:: 10-12-2011

NAME

IEEE_IS_FINITE - Tests for x being greater than negative infinity and less than positive infinity

SYNOPSIS

IEEE_IS_FINITE ([X=]x)

IMPLEMENTATION

Cray Linux Environment (CLE)

STANDARDS

Fortran

IEEE Standard for Binary Floating-point Arithmetic

DESCRIPTION

The IEEE_IS_FINITE intrinsic function returns the value TRUE if -infinity < x < +infinity. Otherwise, it returns the value FALSE. IEEE_IS_FINITE accepts the following argument:

x: Must be of type real.

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

IEEE_IS_FINITE is not invoked if IEEE_SUPPORT_DATATYPE(X) has the value false.

NOTES

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

USE, INTRINSIC :: IEEE_ARITHMETIC

RETURN VALUES

The result type and type parameter is default logical.

The result has the value true if the value of x is finite. That is, the IEEE_CLASS(x) must be one of the following values:

IEEE_NEGATIVE_DENORMAL
IEEE_NEGATIVE_NORMAL
IEEE_NEGATIVE_ZERO
IEEE_POSITIVE_NORMAL
IEEE_POSITIVE_DENORMAL
IEEE_POSITIVE_ZERO

EXAMPLES

Example 1:

USE, INTRINSIC :: IEEE_ARITHMETIC
REAL   x
...! Compute X.
IF (IEEE_IS_FINITE(x)) THEN
...! Do something.
ELSE
...! Do something else.
END IF