large
medium
small
A is a 10-by-1 categorical array.
Display the categories of A.
categories(A)
ans = 3x1 cell array
{'small' }
{'medium'}
{'large' }
Verify That Categories Are Protected
When you create an ordinal categorical array, the categories are always protected.
Use the isprotected function to verify that the categories of A are protected.
tf = isprotected(A)
tf = logical
1
The categories of A are protected.
Assign Value in New Category
If you try to assign a new value that does not belong to one of the existing categories,
then MATLAB® returns an error. For example, you cannot assign the value 'xlarge' to
the categorical array, as in the expression A(2) = 'xlarge', because xlarge is not a
category of A. Instead, MATLAB® returns the error:
Error using categorical/subsasgn (line 68)
Cannot add a new category 'xlarge' to this categorical array
because its categories are protected. Use ADDCATS to
add the new category.
Work with Protected Categorical Arrays