how can i sum X's or R's values that their nl=1?

L =[1 2 0.1 0.2 0.02
    1 4 0.05 0.2 0.02
    1 5 0.08 0.3 0.03
    2 3 0.05 0.25 0.03
    2 4 0.05 0.1 0.01
    2 5 0.1 0.3 0.02
    2 6 0.07 0.2 0.025
    3 5 0.12 0.26 0.025
    3 6 0.02 0.1 0.01
    4 5 0.2 0.4 0.04
    5 6 0.1 0.3 0.03]

nl = L(:,1); nr = L(:,2); R = L(:,3);
X = L(:,4); Bc = j*L(:,5); 
nbr=length(linedata(:,1)); nbus = max(max(nl), max(nr));

i wanna sum X's whose nl = 1....(ans=0.2+0.2+0.3=0.7)

Answer 1

[VIGNESH B S]

Matlab actually takes every column as variables.

In the below shown example sum gives the result as follows ,Output is 2 4 6 8 10.

If you wish to find the sum (1+2+3+4+5) row wise in a n*m matrix -> JUST Trasnpose the matrix and find the sum.

x = [1,2,3,4,5;1,2,3,4,5];
sum(x)

Transpose = x'
sum(Transpose)  %Output here is 15 15.
%If you just want sum of first column here assign the o/p to a variable
%and access the 1st element .. var(1) ->a11+a12+a13.. of matrix x.