mustBeNonnegative

Validate that value is nonnegative

Syntax

mustBeNonnegative(value)

Description

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

mustBeNonnegative calls the ge function to determine if the input is not negative. (since R2026a)

Class support: All numeric classes, logical, and MATLAB^® classes that implement ge.

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 to Nonnegative 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 these types:

• logical or numeric class

• MATLAB classes that implement ge

Example: value = 1 does not generate an error.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string | categorical | datetime | duration | table | timetable
Complex Number Support: Yes

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 Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU 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™.

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

Version History

Introduced in R2017a

R2026a: mustBeNonnegative no longer restricts input data to be real, numeric, or logical

The mustBeNonnegative function no longer calls the isreal, isnumeric, and islogical functions to validate input. As a result, mustBeNonnegative accepts any data type supported by the underlying comparison operator ge (or >=), such as character vectors, strings, and date and time types.

For example, the Interval property definition in MyClass restricts property values using the mustBeNonnegative validation function.

classdef MyClass
   properties
      Interval {mustBeNonnegative}
   end
end

You can now specify the property as a value of type duration.

A = datetime("yesterday");
B = datetime("today");
s = MyClass;
s.Interval = B - A;

In previous releases, specifying the Interval property as a duration value returned this error:

Error setting property 'Interval' of class 'MyClass'. Value must be numeric or logical.

To preserve the behavior of previous releases, explicitly use mustBeReal and mustBeNumericOrLogical in your validation checks. For example, this code preserves the previous behavior of mustBeNonnegative in the Interval property definition.

classdef MyClass
   properties
      Interval {mustBeReal,mustBeNumericOrLogical, ...
                mustBeNonnegative}
   end
end