Making a new variable

Hello, I would like to make a new variable from existing variables. What I want to do is sum up the first column of 3 variables that I have already made and make 1 new variable with the sums in a 1x3 row.

Answer 1

[David Hill]

newVar=[sum(first(:,1),sum(second(:,1),sum(third(:,1)];

[LacAnthony]

Thank you so much!!

Answer 2

[Walter Roberson]

new_variable = [sum(first_variable(:,1)), sum(second_variable(:,1)), sum(third_variable(:,1))];

There is another approach that is slightly more compact but requires that the variables be the same size; the above code does not require that.