MATLAB: Finding unique set from large dataset

Question

Hello!

How would one go about to find a unique set of variables that can depict shortly which variables are used in a large dataset using a matlab code?

For example if the english dictionary is my large dataset, I want the output to be the 26 alphabets-saying these are the unique variables used in your large dataset.

Another example

If x = {"abc", "bcd", "ded"}

I want the output as {"a","b","c","d","e"}

Thanks in advance!

Answer 1

a = cellfun(@(z)regexp(z,'.','match'),x,'un',0);
Output = num2cell(unique([a{:}]))