how to sum matrics inside a cell array?
58 次查看(过去 30 天)
显示 更早的评论
i have 4 matrics inside a cell and i need to sum them all currenyly i use this:
R=R{1}+R{2}+R{3}+R{4}
the original R is a cell with 4 matrics
0 个评论
采纳的回答
dpb
2014-8-6
编辑:dpb
2017-4-22
Oh, misunderstood the query...that's simply
S=plus(R{:})
S =
1.3771 0.5139
1.1590 0.7149
>> all(all(S==R{1}+R{2}))
ans =
1
>>
Just used two cells here, but works for any number. As noted elsewhere sizes must be commensurate.
ERRATUM Does NOT work as written for any number of cells; plus isn't as smart as I was thinking it was/is... :(
Instead use
S=sum(cat(3,R{:}),3);
As another poster noted, all cells must contain conformantly-sized arrays.
NB: The result will be class of the content of the cell (default double, of course).
5 个评论
dpb
2017-4-22
Hmmm....my bad, had tested only for two cells; I was thinking w/o checking that plus was enabled to handle a variable number of arguments but it isn't...see ERRATUM above Answer--dpb
LD
2017-11-26
Is there other methods to solve this problem? This methods is less efficient then the for-loop
更多回答(2 个)
Evan
2014-8-6
编辑:Evan
2014-8-6
Are all the matrices in your cell array the same size? If so, this should work:
% Get random cell array with n cells. Here n = 3
A = {rand(4) rand(4) rand(4)}
n = size(A,2);
% Get size of matrices in cell.
matSize = size(A{1},1);
B = reshape(cell2mat(A),matSize,[],n);
% Sum 3D matrix along 3rd dimension
C = sum(B,3);
If they're different sizes, this either wont work or we need more information about how you want the different sizes handles (e.g. trimming, padding, etc.).
0 个评论
dpb
2014-8-6
One way, seems should be better but it's still first cup o' coffee this morning...
>> R={rand(2) rand(3)}
R =
[2x2 double] [3x3 double]
>> sum(cellfun(@(x) sum(x(:)),R))
ans =
8.7056
>>
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Logical 的更多信息
产品
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!