mustBeNonnegative

Validate that value is nonnegative

Syntax

mustBeNonnegative(value)

Description

mustBeNonnegative(value) throws an error if value is negative. This function does not return a value.

mustBeNonnegative calls these functions to determine if the input is not negative:

• isreal

• isnumeric or islogical

• ge

Class support: All numeric classes, logical, and MATLAB^® classes that overload the functions called by mustBeNonnegative.

Examples

Validate That Values Are Not Negative

Use mustBeNonnegative to validate that the input contains only nonnegative values.

The randn function creates normally distributed random numbers.

A = randn(1,5);

Validate that the random numbers are nonnegative.

mustBeNonnegative(A)

Value must be nonnegative.

Restrict Property Values

This class restricts the value of Prop1 to nonnegative values.

classdef MyClass
   properties
      Prop1 {mustBeNonnegative}
   end
end

Create an object and assign a value to its property.

obj = MyClass;
obj.Prop1 = -10;

Error setting property 'Prop1' of class 'MyClass'. Value must be nonnegative.

When you assign a value to the property, MATLAB calls mustBeNonnegative with the value being assigned to the property. mustBeNonnegative issues an error because the value -10 is negative.

Restrict Function Argument Values

This function declares two input arguments. Input lower must be not be positive and input upper must be positive.

function r = mbNonnegative(lower,upper)
    arguments
        lower {mustBeNonpositive}
        upper {mustBeNonnegative}
    end
    x = lower*pi:upper*pi;
    r = sin(x);
end

Calling the function with a value for upper that does not meet the requirements of mustBeNonnegative results an error.

r = mbNonnegative(-12,-4);

Error using mbNonnegative (line 4)
 r = mbNonnegative(-12,-4);
                       ^^
Invalid argument at position 2. Value must be nonnegative.

Input Arguments

value — Value to validate

scalar | array

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

• logical or numeric class

• MATLAB classes that implement ge, isreal, and either isnumeric or islogical

Example: value = 1 does not generate an error.

Tips

• mustBeNonnegative 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™.

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

The mustBeNonnegative function fully supports GPU arrays. To run the function on a GPU, specify the input data as a gpuArray (Parallel Computing Toolbox). For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).

Version History

Introduced in R2017a