changing dimension in a loop

Question

Rafael Schwarzenegger 2018-10-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/422001-changing-dimension-in-a-loop

评论： Rafael Schwarzenegger 2018-10-3

Hello,

I would like to be changing the dimension in a loop. In other words, I would like to re-write this code in a single loop

e1=mean(reshape(A(:,1,:,:,:),1,[]));
e2=mean(reshape(A(:,2,:,:,:),1,[]));
e3=mean(reshape(A(:,3,:,:,:),1,[]));
vp=var([e1 e2 e3]);
s(1) = vp/v;
e1=mean(reshape(A(:,:,1,:,:),1,[]));
e2=mean(reshape(A(:,:,2,:,:),1,[]));
e3=mean(reshape(A(:,:,3,:,:),1,[]));
vp=var([e1 e2 e3]);
s(2) = vp/v;

So that I have for i=1:2 an expression for s(i).

Thank you.

Best,

Rafael

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Stephen23 2018-10-3

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/422001-changing-dimension-in-a-loop#answer_339559

编辑：Stephen23 2018-10-3

在 MATLAB Online 中打开

There is a neat trick for that: simply put the indices into a cell array, which you can then redefine using indexing.

S = nan(1,2);
for k = 1:2
     C = {':',':',':',':',':'};
     C{1+k} = 1;
     e1 = mean(reshape(A(C{:}),1,[]));
     C{1+k} = 2;
     e2 = mean(reshape(A(C{:}),1,[]));
     C{1+k} = 3;
     e3 = mean(reshape(A(C{:}),1,[]));
     vp = var([e1,e2,e3]);
     S(k) = vp/v;
end