MATLAB Application Program Interface Reference

True if value is Not-a-Number

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

Arguments

value

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

Returns

true if value is Not-a-Number; otherwise, returns false.

Description

Call mxIsNaN to determine whether or not value is equal to NaN. NaN is the IEEE arithmetic representation for Not-a-Number. A NaN is obtained as a result of mathematically undefined operations such as

0.0/0.0
inf-inf

The system understands a family of bit patterns as being equivalent to NaN. In other words, NaN is not a single value, rather it is a family of numbers that MATLAB (and other IEEE-compliant applications) interpret as being equal to Not-a-Number.