I would like to sum up rows over specific ranges specified by an array. I do not know if there is a vectorised solution to it.
I have a matrix A say
A = [1,0,0,2;
I have an array B specifying the ranges of rows I want to sum up:
B shows that I would like to sum up the first 2 rows, and then the next 1 row, and then the next 2 rows. sum(B) equals to the total number of rows in A.
The output C has the same number of rows as B and the same number of columns as A:
C = [1, 3, 1, 2;
1, 2, 3, 4;
1, 1, 0, 2];