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Validate that value is finite



mustBeFinite(value) throws an error if value is not finite. A numeric value is finite if it is not NaN or Inf. This function does not return a value.

mustBeFinite calls the following function to determine if the input is finite:

Class support: All numeric classes, logical, char, and MATLAB® classes that overload isfinite.

This function ignores input arguments that are empty values. Therefore, no error is thrown when the property or function argument value is empty.


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Use mustBeFinite to validate that no array elements are NaN or Inf.

d = 0:9;
A = 1./d;
Error using mustBeFinite (line 13)
Value must be finite.

The division by d resulted in one element becoming Inf, which causes an error.

This class restricts the value of Prop1 to finite values.

classdef MyClass
      Prop1 {mustBeFinite}

Create an object and assign a value to its property.

d = 0:9;
obj = MyClass;
obj.Prop1 = 1./d;
Error setting property 'Prop1' of class 'MyClass':
Value must be finite.

When you assign a value to the property, MATLAB calls mustBeFinite with the value being assigned to the property. mustBeFinite issues an error because the result of division by 0 is Inf.

This function declares an input argument that must be a vector of doubles that contain no Inf or NaN elements.

function s = mbFinite(x)
        x (1,:) double {mustBeFinite}
    n = length(x);
    m = sum(x)/n;
    s = sqrt(sum((x-m).^2/n));

Calling the function with an input that does not meet the requirement of mustBeFinite results in an error.

values = [12.7, 45.4, 98.9, Inf, 53.1];
s = mbFinite(values);
Error using mbFinite
Invalid input argument at position 1. Value must be finite.

Input Arguments

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Value to validate, specified as a scalar or an array of one of the following:

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical
Complex Number Support: Yes


  • mustBeFinite is designed to be used for property and function argument validation.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Introduced in R2017a