mustBeVector

Validate that value is vector

Since R2020b

Syntax

mustBeVector(value)

mustBeVector(value,"allow-all-empties")

Description

mustBeVector(value) throws an error if value is not a vector. A vector has dimension of 1-by-n or n-by-1. This function does not return a value.

mustBeVector(value,"allow-all-empties") throws an error if value is not a vector or not an empty array.

mustBeVector calls the following function to determine if the input is a vector:

• isvector

Class support: All numeric classes, logical, and MATLAB^® classes that overload isvector.

Examples

Determine if Value Is a Vector

Determine if value 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 the function input to a numeric vector using mustBeVector and mustBeNumeric. Allow an empty value using the mustBeVector allow-all-empties option.

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 {mustBeVector(DailyTotals,'allow-all-empties'), mustBeNumeric}
    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 or column vector

Value to validate, specified as a row or column vector.

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 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™.

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

Version History

Introduced in R2020b