Assigning the Nth element of Cell Array to another Array

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tinkyminky93 2022-6-5

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1734235-assigning-the-nth-element-of-cell-array-to-another-array

编辑： Voss 2022-6-5

Hello, I have an cell array with 1000 rows and inside of this rows I have a 3 word. I am taking the 2nd element of this rows and want to assign these values to another array. In other words array_temp(i,1) = array(i,2). I want to do it with for loop. How can I do it?

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Jan 2022-6-5

编辑：Jan 2022-6-5

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What does this mean: "inside of this rows I have a 3 word"?

Prefer to post some code, which reproduces a small set of test data.

What's wrong with this:

array_temp = array(:,2);

Why do you need a loop?

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Answer 1

Voss 2022-6-5

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https://ww2.mathworks.cn/matlabcentral/answers/1734235-assigning-the-nth-element-of-cell-array-to-another-array#answer_979415

编辑：Voss 2022-6-5

在 MATLAB Online 中打开

If array is a 1000-by-3 cell array, then you already know how to do it (here I'll use a 10-by-3 cell array):

% creating a 10-by-3 cell array of 'words':
array = mat2cell(char(randi(26,10,15)-1+'A'),ones(10,1),[5 5 5]);
disp(array);
    {'PVCXI'}    {'ZNTRT'}    {'TSOZI'}
    {'KGKDP'}    {'LDZKJ'}    {'QEUIN'}
    {'LEFNA'}    {'KKHYG'}    {'XWEKS'}
    {'MXUUO'}    {'KKODQ'}    {'UQYZO'}
    {'OCZJK'}    {'LKTBV'}    {'DLDUU'}
    {'NDXWY'}    {'ITHAE'}    {'DFDHJ'}
    {'NRREZ'}    {'LLRFH'}    {'WKSJG'}
    {'BRKWE'}    {'BRULF'}    {'RALHF'}
    {'HNTDE'}    {'QYBCZ'}    {'IGFCE'}
    {'VVNNJ'}    {'QSGME'}    {'JYBVR'}
n_rows = size(array,1);
array_temp = cell(n_rows,1);
for i = 1:n_rows
    array_temp(i,1) = array(i,2);
end
disp(array_temp);
    {'ZNTRT'}
    {'LDZKJ'}
    {'KKHYG'}
    {'KKODQ'}
    {'LKTBV'}
    {'ITHAE'}
    {'LLRFH'}
    {'BRULF'}
    {'QYBCZ'}
    {'QSGME'}

But a for loop is not necessary:

array_temp = array(:,2);
disp(array_temp);
    {'ZNTRT'}
    {'LDZKJ'}
    {'KKHYG'}
    {'KKODQ'}
    {'LKTBV'}
    {'ITHAE'}
    {'LLRFH'}
    {'BRULF'}
    {'QYBCZ'}
    {'QSGME'}

On the other hand, if array is a 1000-by-1 cell array with each element being a 1-by-3 cell array (again, using size 10 instead of 1000 for demonstration), you can do it with a for loop like this:

% creating the cell array of cell arrays:
array = num2cell(array,2);
disp(array);
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}
    {1×3 cell}
n_rows = size(array,1);
array_temp = cell(n_rows,1);
for i = 1:n_rows
    array_temp(i,1) = array{i}(2);
end
disp(array_temp);
    {'ZNTRT'}
    {'LDZKJ'}
    {'KKHYG'}
    {'KKODQ'}
    {'LKTBV'}
    {'ITHAE'}
    {'LLRFH'}
    {'BRULF'}
    {'QYBCZ'}
    {'QSGME'}

But again, an explicit for loop is not necessary:

array_temp = cellfun(@(x)x{2},array,'UniformOutput',false);
disp(array_temp);
    {'ZNTRT'}
    {'LDZKJ'}
    {'KKHYG'}
    {'KKODQ'}
    {'LKTBV'}
    {'ITHAE'}
    {'LLRFH'}
    {'BRULF'}
    {'QYBCZ'}
    {'QSGME'}

If array is of some form besides one of these two, please post an example.