# MATLAB: I want to sum up specific array in a matrix

sum

For example If I have a matrix like this
x = [ 2.356 37
1.351 39
4.394 37
3.622 39
4.489 39
3.135 37
6.653 39 ]
I want to sum up the values that are specific to 37 and 39 seperatly only if it is alternative. If 39 and 37 are not alternative like in 4th and 5 th row wants to add that to the next subsecuent value in this case it is 37.
Some of the 37 should be (2.356+4.394+4.489+3.135), 39 should be (1.351+3.622+6.653). Please help in getting a matlab code for this!
``function [sum_37, sum_39] = compute_sum(x)    sum_37 = 0;    sum_39 = 0;    found_37 = false;    found_39 = false;    for i = 1 : length(x)        if x(i, 2) == 37            if ~found_37                 sum_37 =  sum_37 + x(i, 1);                found_37 = true;                found_39 = false;            else                sum_39 =  sum_39 + x(i, 1);            end            else            if ~found_39                 sum_39 =  sum_39 + x(i, 1);                found_39 = true;                found_37 = false;            else                sum_37 =  sum_37 + x(i, 1);            end        end    endend``