This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English version of the page.

Note: This page has been translated by MathWorks. Click here to see
To view all translated materials including this page, select Country from the country navigator on the bottom of this page.


Validate that value is negative or issue error





mustBeNegative(A) issues an error if A is not negative. A value is negative if it is less than zero. This function does not return a value.

mustBeNegative accepts user-defined objects if the class of the object implements these methods:

This function ignores input arguments that are empty values. No error is thrown if the property value is empty.


collapse all

Use mustBeNegative to validate that the input contains only negative values.

The rand function creates uniformly distributed random numbers in the interval (0,1). Test the array after the subtraction to validate that all values are negative. If not, mustBeNegative issues an error.

A = rand(1,5) - 0.75;
Error using mustBeNegative (line 14)
Value must be negative.

This class constrains the value of Prop1 to negative values.

classdef MyClass
      Prop1 {mustBeNegative}

Create an object and assign a value to Prop1.

obj = MyClass;
obj.Prop1 = rand(1,5) - 0.75;
Error setting property 'Prop1' of class 'MyClass':
Value must be negative.

When you assign a value to the property, MATLAB® calls mustBeNegative with the value being assigned to the property. mustBeNegative issues an error if the any of the elements in the array are not negative.

Input Arguments

collapse all

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

Extended Capabilities

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

Introduced in R2017a