External Interfaces Reference

mxIsNaN

Determine if value is NaN (Not-a-Number)

Fortran Syntax

• integer*4 function mxIsNaN(value)
  integer*4 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 (and other IEEE-compliant applications) uses to represent an error condition or missing data.

See Also

mxIsFinite, mxIsInf

mxIsLogical

mxIsNumeric

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