Problem with categorical arrays

I have a problem with the categorical function. Some variables of my problem are of the following type (It is a reduced form of my problem):

I want to convert it to a categorical array but the categorical function gives me the following error:

Error using categorical (line 321)
Could not find unique values in DATA using the UNIQUE function.
Caused by:
    Error using cell/unique (line 85)
    Input A must be a cell array of strings.

This is the code I use for convert it in a categorical array.

VarA.VarA = categorical(VarA.VarA);

[Jan Orwat]

you are trying to make categorical array from a variable of mixed data types.

categorical([1 2 3 5 2 1])
categorical({'str1' 'str2'})

works, but

categorical({'str1' 'str2' 1 3 2 1})

does not. It works the same way for tables. Check categorical documentation for more information.

To solve this problem you may change numerical data to strings.

[Stephen23]

@Jan Orwat: you should put this as an answer: I would vote for it, and it might get accepted too.

[Manuel Valenciano]

How can I change numerical data to strings?

[Brendan Hamm]

idx = cellfun(@isnumeric,A);
Q = cellfun(@num2str,A(idx),'UniformOutput',false)
A(idx) = Q;

[Manuel Valenciano]

Thank you for your answer

Answer 1

[Jan Orwat]

(Copied from comments as suggested.)

You are trying to make categorical array from a variable of mixed data types.

categorical([1 2 3 5 2 1])
categorical({'str1' 'str2'})

works, but

categorical({'str1' 'str2' 1 3 2 1})

does not. It works the same way for tables. Check categorical documentation for more information.

To solve this problem you may change numerical data to strings.