Is there a multiplicative accumarray function?

1 view (last 30 days)
Christopher
Christopher on 14 Mar 2014
Edited: the cyclist on 14 Mar 2014
I am using accumarray to additively accumulate numbers with a code like the following:
wts = accumarray([P(:,2),P(:,1)],P(:,3),size(net));
Is there a function, or a simple vectorized method, to do the exact same thing with one difference: instead of adding the numbers, multiply them?
If accumarray finds numbers N1, N2, N3... it will add them as N1+N2+N3...
However, I want a function to multiply them as N1*N2*N3...
Thanks

Answers (1)

the cyclist
the cyclist on 14 Mar 2014
Edited: the cyclist on 14 Mar 2014
accumarray() takes an optional fourth argument, which is the function to apply. You should be able to add @prod to do what you want.
Here is the example from the documentation:
val = 101:105;
subs = [1 1; 2 1; 2 3; 2 1; 2 3];
A = accumarray(subs, val, [2 4], @prod, 0, true)
Read
doc accumarray
for details.

Categories

Find more on Data Types in Help Center and File Exchange

Tags

Products

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!