Efficient application of unique and strcat functions

I use the following code on several occasions to keep only the rows with the condition that X elements don't repeat:

[~, ind,~] = unique(strcat(a(:,2)a(:, 6)));
a = a(ind,:);

In this case I keep the rows that have different combinations of the elements of column 2 and 6.

I use the functions unique and strcat because they work for cell type variables with both strings and numbers . The problem is that this code is not efficent and takes a lot of time to run. I was wondering if someone had a better solution. Thank you

Answer 1

[Matt J]

Looks like you need the 'rows' flag in your call to unique. Also, it might help to avoid requesting additional output arguments that you don't need.

    a = unique(strcat(a(:,2),a(:,6)),'rows');

Note that the use of ~ output arguments isn't the same as requesting fewer outputs. The ~ outputs will still be computed. They just won't be stored anywhere.