mustBeVector

R2026b

Validate that value is vector

Syntax

mustBeVector(value)

Description

mustBeVector(value) throws an error if value is not a vector. A vector has dimensions of 1-by-n or n-by-1. This function does not return a value. mustBeVector calls the isvector function to determine if the input is a vector.

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

Examples

Determine If Value Is Vector

Use mustBeVector to validate that a is a row or column vector.

a = rand(2);
mustBeVector(a)

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

mustBeVector throws an error because the input is a 2-by-2 array.

Reshape the value a to a row vector.

b = reshape(a,[1,numel(a)])
mustBeVector(b)

mustBeVector executes without throwing an error or returning a value.

Validate That Function Input Is Numeric Vector

Use an arguments block to restrict a function input to a numeric vector using mustBeVector and mustBeNumeric.

The WeeklyTotals function sums the elements of the input vector.

function r = WeeklyTotals(DailyTotals)
    arguments
        DailyTotals {mustBeVector,mustBeNumeric}
    end
    r = sum(DailyTotals);
end

Passing a row or column vector returns the sum of the vector elements.

r = WeeklyTotals(1:5)

r = 
    15

Input Arguments

value — Value to validate

row or column vector

Value to validate, specified as a row or column vector. If you specify a value that is not a vector, 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

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

Version History

Introduced in R2020b

R2026b: mustBeVector(value,"allow-all-empties") is not recommended

mustBeVector(value,"allow-all-empties") throws an error if value is not a vector or not an empty array. Stating in R2026b, this syntax is not recommended.

Instead, use the mustBeVectorOrEmpty validation function to validate that a value is either a vector or an empty array. You can update your code by replacing occurrences of mustBeVector(value,"allow-all-empties") with mustBeVectorOrEmpty(value). However, there are no plans to remove the mustBeVector(value,"allow-all-empties") syntax.