How i accumulate multiple variables?

Hi,

I have an array, where column 1 to 3 are descriptive, and column 4 is the value. For example:

1 1 1 a
1 1 2 b
1 2 1 c
1 2 2 d
2 1 1 e
2 1 2 f
2 2 1 g
2 2 2 h
3 1 1 i
3 1 2 j
3 2 1 k
3 2 2 l

I want to totalize this array by column 3 descriptive value, so the result is this:

1 1 (a+b)
1 2 (c+d)
2 1 (e+f)
2 2 (g+h)
3 1 (i+j)
3 2 (k+l)

I tried with accumarray using as subs columns 1 and 2, and it gives the result i Want, but in a different form:

(a+b)    (c+d)
(e+f)    (g+h)
(i+j)    (k+l)

Please, have any ideas?

Answer 1

[dpb]

1. out=out(:); % just reshape to column vector
2. Use k=2*(i-1)+j; % for index vector where i,j ==> a(:,1), a(:,2), respectively.