Determine whether input is infinite
Call mxIsInf to determine whether value is equal to infinity or minus infinity. MATLAB® software 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), mxIsInf returns false. In other words, NaN is not equal to infinity.