how to sum matrics inside a cell array?
52 ビュー (過去 30 日間)
古いコメントを表示
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 件のコメント
採用された回答
dpb
2014 年 8 月 6 日
編集済み: dpb
2017 年 4 月 22 日
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 件のコメント
dpb
2017 年 4 月 22 日
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 年 11 月 26 日
Is there other methods to solve this problem? This methods is less efficient then the for-loop
その他の回答 (2 件)
Evan
2014 年 8 月 6 日
編集済み: Evan
2014 年 8 月 6 日
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 件のコメント
dpb
2014 年 8 月 6 日
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
>>
参考
カテゴリ
Help Center および File Exchange で Logical についてさらに検索
製品
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!