How to remove Nans from matrix

Question

Ian 2013-9-10

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I have a matrix (size 123317x6), and every 128 rows I have 3 nans on the last three columns of that thoses rows. Now what I want to do is remove all the NaNs completely without removing that row or column (just the NanNs) The data on the next row then needs to be moved up to where the Nans were. I will give you a quick example.

so I want this matrix:-

M=

1 3 6 nan nan nan 4 5 4 1 3 4 1 2 2 6 3 1 1 3 4 nan nan nan 3 4 5 6 7 8

M=

1 3 6 4 5 4 1 3 4 1 2 2 6 3 1 1 3 4 3 4 5 6 7 8

Hope this example explains what I want better!

Any help would be greatly appreicated.

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Answer 1

Azzi Abdelmalek 2013-9-10

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编辑：Azzi Abdelmalek 2013-9-10

在 MATLAB Online 中打开

out=reshape(M(~isnan(M)),[],size(M,2))

Edit

M can not be reshaped unless we add some nan at the end of M

%---------Your array-------------------
M=rand(123317,6);
M(128:128:n,end-2:end)=nan; 
%-----------------------------------------
n=size(M,1);
M=M(~isnan(M));
M(end:end+mod(6-mod(numel(M),6),6))=nan;
M=reshape(M,[],6);

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Geert 2013-9-10

在 MATLAB Online 中打开

I like your answer more than mine. There is however a small mistake, it should be:

out=reshape(M(~isnan(M)),[],size(M,2)-3)

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Answer 2

Andrei Bobrov 2013-9-10

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编辑：Andrei Bobrov 2013-9-10

在 MATLAB Online 中打开

out = resM(M==M)

ADD

M1 = M';
out = reshape(M1(M1==M1),size(M,2),[])';

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Answer 3

Geert 2013-9-10

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在 MATLAB Online 中打开

If it are exactly 3 NaN's per row, you could do something like this:

M = [1 3 6 nan nan nan 4 5 4 1 3 4 1 2 2;
     6 3 1 1 3 4 nan nan nan 3 4 5 6 7 8];
M_new = zeros(size(M,1), size(M,2)-3);
for ii = 1:size(M,1)
    M_new(ii,:) = M(ii,~isnan( M(ii,:)));
end