How to extract a column from cell arrays matrix?

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Abdulaziz Abutunis 2017-4-29

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https://ww2.mathworks.cn/matlabcentral/answers/337932-how-to-extract-a-column-from-cell-arrays-matrix

评论： Abdulaziz Abutunis 2018-8-16

采纳的回答： per isakson

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Dear MATLAB users,

I wish I got your help for this problem. I have built a cell arrays as a matrix as follow

for k=1:5
out{k}(1,:}=
out{k}(2,:}=
out{k}(3,:}=
end

I am trying to extract the the first element in first array from each cell. i have tried this out{1:5}(1,1) but it does not work however if i type out{1}(1,1) this give the first element but in specific cell also out{1:5} shows all cell matrices. The error I saw when i tried out{1:5}(1,1) was Expected one output from a curly brace or dot indexing expression, but there were 5 results.

Thank you in advance. Best Aziz

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Abdulaziz Abutunis 2017-4-29

Thank you Stephen, you are totally right. I just do some adjustment to an old code. I will consider your advice in the future. Appreciate it

Walter Roberson 2017-4-29

Abdulaziz Abutunis comments to Stephen:

He did not solve the problem but he did give a good advice to avoid this problem in the future. he even gave more than one option.

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Answer 1

per isakson 2017-4-29

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One way

>> cellfun( @(a) a(1,1), out )
ans =
    0.9572    0.0357    0.7060    0.0344    0.7094

however, a for-loop might be a better choice

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per isakson 2017-4-29

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@Abdulaziz Abutunis, Create some sample data

for ii = 1:5
    for jj = 1:3
        out{ii}(jj,:) = ii*100 + jj*10 + (1:3)';
    end
end

Inspect the value of the first cell

>> out{1}
ans =
   111   112   113
   121   122   123
   131   132   133

Inspect one specific element of the value of the first cell

>> out{1}(3,2)
ans =
   132
>>

Caveat: I'm not sure I understood your question.

Abdulaziz Abutunis 2018-8-16

I should have said thanks again a long time ago:). I already used your suggestions

Thanks a lot

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Answer 2

Image Analyst 2017-4-29

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编辑：Image Analyst 2017-4-29

You can't have out{k}(1,:} because you got two closing braces and no closing parenthesis. Maybe you meant out{k}(1,:). See the FAQ: http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F and try to avoid cell arrays in most cases, definitelyif you have rectangular numerical array of constant dimensions, it just complicates things.