isinf Subroutine

Purpose

Tests for infinity.

Syntax

#include <math.h>

int isinf (x)
real-floating x;

Description

The isinf macro determines whether its argument value is an infinity (positive or negative). An argument represented in a format wider than its semantic type is converted to its semantic type. Determination is based on the type of the argument.

Parameters

Return Values

The isinf macro returns a nonzero value if its argument has an infinite value.