isprotected

Determine if categories of categorical array are protected

Syntax

tf = isprotected(A)

Description

tf = isprotected(A) returns logical 1 (true) if the categories of a categorical array are protected. Otherwise, isprotected returns logical 0 (false).

• true — When you assign new values to B, the values must belong to one of the existing categories. Therefore, you only can combine arrays that have the same categories. To add new categories to B, you must use the addcats function.

• false — When you assign new values to B, the categories update automatically. Therefore, you can combine (nonordinal) categorical arrays that have different categories. The categories can update to include the categories from both arrays.

Examples

Determine if Categories Are Protected

Create a categorical array containing the sizes of 10 objects. Use the names small, medium, and large for the values S, M, and L.

valueset = ["S","M","L"];
catnames = ["small","medium","large"];
A = categorical(["M";"L";"S";"S";"M";"L";"M";"L";"M";"S"], ...
                valueset,catnames,Ordinal=true)

A = 10×1 categorical
     medium 
     large 
     small 
     small 
     medium 
     large 
     medium 
     large 
     medium 
     small 

Display the categories of A.

categories(A)

ans = 3×1 cell
    {'small' }
    {'medium'}
    {'large' }

Determine if the categories of A are protected.

tf = isprotected(A)

tf = logical
   1

Because A is an ordinal categorical array, the categories are protected. If you try to add a new value that does not belong to one of the existing categories, for example A(11) = "xlarge", then an error is returned.

First, use addcats to add a new category for xlarge.

A = addcats(A,"xlarge",After="large");

You can add a value for xlarge because the category now exists.

A(11) = "xlarge"

A = 11×1 categorical
     medium 
     large 
     small 
     small 
     medium 
     large 
     medium 
     large 
     medium 
     small 
     xlarge 

A is now an 11-by-1 categorical array with four categories, such that small < medium < large < xlarge.

Input Arguments

A — Input array

categorical array

Input array, specified as a categorical array.

The categories of ordinal categorical arrays are always protected.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

The isprotected function fully supports tall arrays. For more information, see Tall Arrays.

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

This function fully supports code generation. For more information, see Code Generation for Categorical Arrays (MATLAB Coder).

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

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 R2013b