External Interfaces/API Reference

mxIsInf

True if value is infinite

C Syntax

• #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, and false otherwise.

Description

Call mxIsInf to determine whether or not value is equal to infinity or minus infinity. MATLAB stores the value of infinity in a permanent variable named Inf, which represents IEEE arithmetic positive infinity. The value of the variable, 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.

Examples

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

See Also

mxIsFinite, mxIsNaN

mxIsFull (Obsolete)

mxIsInt8