How to get the average of a subset of data in a matrix?
3 views (last 30 days)
Show older comments
I am having some difficulty finding the average of some subsets of data. For example, given the following matrix:
ItemA 7
ItemA 8
ItemA 9
ItemB 10
ItemB 12
ItemB 14
ItemC 8
ItemC 16
ItemC 0
Given the above data, I would like to find the average of item A, B, and C individually. So it should return that Item A the average is 8, Item B the average is 12, and item C the average is 8.
The above data is just an example, the actual data is many more items so I need it to work for an unknown amount of items.
If you have any questions feel free to ask,
Thanks
7 Comments
Accepted Answer
Andrei Bobrov
on 5 Nov 2013
C = {'ItemA' 1 3
'ItemA' 2 5
'ItemA' 3 2
'ItemB' 2 4
'ItemB' 1 3
'ItemC' 2 9
'ItemC' 9 2};
[a,ii,ii] = unique(C(:,1));
[j1,j2] = ndgrid(ii,1:2);
b = cat(1,C{:,2:3});
out = [a, accumarray([j1(:),j2(:)],b,[],@(x){mean(x)})];
More Answers (0)
See Also
Categories
Find more on ANOVA 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!