access array multiple times and calculate some value
3 views (last 30 days)
Show older comments
dleal on 28 Jul 2022
Answered: David Hill on 28 Jul 2022
Hi all, I would like to know if there's a faster way that using a foor loop for this:
a = rng(99);
A = randn(1,100);
B = [20 23; 30 37; 51 55; 78 100 ];
For each row B, I would like to slice A from the first column to the second column value, and then apply some function, for example, sum.
So for example, the first computation would be sum(A(20:23)), then sum(A(30:37)) ... sum(A(78:100)).
The for loop would be:
for ii = 1:size(B,1)
sum(A(B(ii,1) : B(ii,1) );
Could I program this such that it results in a faster calculation?
David Hill on 28 Jul 2022
Shorter way to write it, but will not improve speed.
Find more on Multidimensional Arrays in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!Start Hunting!