MATLAB^®

mxIsNaN (C and Fortran) - Determine whether input is `NaN` (Not-a-Number)

C Syntax

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

Fortran Syntax

integer*4 mxIsNaN(value)
real*8 value

Arguments

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

Returns

Logical 1 (true) if value is NaN (Not-a-Number), and logical 0 (false) otherwise.

Description

Call mxIsNaN to determine whether or not value is 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 representing NaN. In other words, NaN is not a single value; rather, it is a family of numbers that MATLAB software (and other IEEE-compliant applications) uses to represent an error condition or missing data.

C Examples

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

For additional examples, see findnz.c and fulltosparse.c in the refbook subdirectory of the examples directory.

mxIsNaN (C and Fortran) - Determine whether input is NaN (Not-a-Number)