MATLAB Application Program Interface Reference

True if value is infinite

#include "matrix.h"
bool mxIsInf(double value);

Arguments

value

The double-precision, floating-point number that you are testing.

Returns

true if value is infinite; otherwise, returns false.

Description

Call mxIsInf to determine whether or not value is equal to infinity. MATLAB stores the value of infinity in a permanent variable named inf, which represents IEEE arithmetic positive infinity. The value of inf is built into the system; you cannot modify it.

Operations that return infinity include

Division by 0. For example, 5/0 returns infinity.
Operations resulting in overflow. For example, exp(10000) returns infinity because the result is too large to be represented on your machine.

If value equals NaN (Not-a-Number), then mxIsInf returns false. In other words, NaN is not equal to infinity.

Example

See mxIsInf.c in the mx subdirectory of the examples directory.