mustBeVectorOrEmpty

R2026b

Validate that value is vector or empty

Since R2026b

Syntax

mustBeVectorOrEmpty(value)

Description

mustBeVectorOrEmpty(value) throws an error if value is not a vector or an empty array. This function does not return a value. mustBeVectorOrEmpty calls the isvector and isempty functions to determine if the input is a vector or an empty array.

Class support: All numeric classes, logical, char, string, and MATLAB^® classes that implement isvector and isempty.

Examples

Determine If Value Is Vector Or Empty Array

Use mustBeVectorOrEmpty to validate that a value is a vector or an empty array.

Create a 2-by-2 matrix and test whether it is a vector. mustBeVectorOrEmpty throws an error.

A = ones(2);
mustBeVectorOrEmpty(A)

Value must be a 1-by-n vector, an n-by-1 vector, or empty.

Next, create a 0-by-3 empty array and test whether it is an empty array. In this case, mustBeVectorOrEmpty does not throw an error.

A = zeros(0,3);
mustBeVectorOrEmpty(A)

Validate That Function Input Is Vector Or Empty Array

Use an arguments block to restrict a function input to a vector or an empty array using mustBeVectorOrEmpty.

The WeeklyTotals function sums the elements of the input vector. If the input is empty ([]), the sum is returned as zero.

function r = WeeklyTotals(DailyTotals)
    arguments
        DailyTotals {mustBeVectorOrEmpty}
    end
    if isempty(DailyTotals)
        r = 0;
    else
        r = sum(DailyTotals);
    end
end

Passing an empty value to the function is allowed.

r = WeeklyTotals([])

r = 
    0

Input Arguments

value — Value to validate

row vector | column vector | empty array

Value to validate, specified as a row vector, column vector, or empty array. If you specify a value that is not a vector or an empty array, the function throws an error.

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

Tips

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

Version History

Introduced in R2026b