new array using average row of the old array

2013 10 13
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更新时间：2013 10 13
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I have an array M(1000,1000) and i want to build a new array N(1000,1000), where each element of N has the old value minus the average of its row (in M). If the element is zero no action will be taken. Also, from the average the zeros should be excluded.
Can you help me?
thank you in advance

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 采纳的回答

Azzi Abdelmalek
Azzi Abdelmalek 2013-10-13
编辑：Azzi Abdelmalek 2013-10-13

1 个投票

Edit
out=bsxfun(@minus,M,mean(M,2)).*not(~M)
%or
idx=M==0;
out=bsxfun(@minus,M,mean(M,2));
out(idx)=0

6 个评论
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babis
babis 2013-10-13
thank you for your answer but with this commands the average of the row also counts the elements with zero value and i want them to be excluded.
Azzi Abdelmalek
Azzi Abdelmalek 2013-10-13
Do you want to exclude all the rows with zeros
Azzi Abdelmalek
Azzi Abdelmalek 2013-10-13
If you want to exclude all the rows with zeros
idx=any(~M,2)
out=bsxfun(@minus,M,mean(M,2))
out(idx,:)=M(idx,:)
babis
babis 2013-10-13
dear azzi i want to exclude the zeros when calculating the average. for example in a row like [1 4 7 3 0 0 2 1] the average will be 18/6=3 not 18/8=2.25 thank you again
Azzi Abdelmalek
Azzi Abdelmalek 2013-10-13
编辑：Azzi Abdelmalek 2013-10-13
Ok try this
idx=M==0;
moyenne=sum(M,2)./sum(not(~M),2)
out=bsxfun(@minus,M,moyenne)
out(idx)=0
babis
babis 2013-10-13
thanks again this will do it

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更多回答（1 个）

Andrei Bobrov
Andrei Bobrov 2013-10-13

0 个投票

ii = M == 0;
out = bsxfun(@minus,M,sum(M,2)./sum(~ii,2));
out(ii) = 0;

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