How to convert a cell array to a compatible matrix?

Question

Nandha Kumar 2021-7-16

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/879753-how-to-convert-a-cell-array-to-a-compatible-matrix

评论： Nandha Kumar 2021-7-17

I have a cell array which is filled with matrices of varying size, could you help me to convert it to matrix with filling zeros at in between columns,

in this case the matrix size is ought ot be 41x 41 of double type.

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KSSV 2021-7-16

Fill the empty cells with appropriate zero matrices and use Cell2mat.

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Answer 1

Jan 2021-7-16

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链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/879753-how-to-convert-a-cell-array-to-a-compatible-matrix#answer_748178

编辑：Jan 2021-7-16

在 MATLAB Online 中打开

CC = {rand(9,9), rand(5,4), rand(5,4), rand(6,4), rand(6,4), rand(8,4), rand(8,4), rand(9,4), rand(9, 4); ...
    rand(4,5), rand(4,4), [], [], [], [], [], [], []; ...
    [], [], rand(4,4), [], [], [], [], [], []; ...
    rand(4,6), [], [], rand(4,4), [], [], [], [], []; ...
    [], [], [], [], rand(4,4), [], [], [], []; ...
    rand(4,6), [], [], [], [], rand(4,4), [], [], []; ...
    [], [], [], [], [], [], rand(4,4), [], []; ...
    rand(4,6), [], [], [], [], [], [], rand(4,4), []; ...
    [], [], [], [], [], [], [], [], rand(4,4)};
C     =  CC;
S1    = cellfun('size', C, 1);
maxS1 = max(S1, [], 2);
S2    = cellfun('size', C, 2);
maxS2 = max(S2, [], 1);
for i2 = 1:size(C, 2)
   for i1 = 1:size(C, 1)
       X = C{i1, i2};
       if size(X, 1) < maxS1(i1) || size(X, 2) < maxS2(i2)
          X(maxS1(i1), maxS2(i2)) = 0;
          C{i1, i2} = X;
       end
   end
end
Result = cell2mat(C);

Cheaper:

C     = CC;
S1    = cellfun('size', C, 1);
maxS1 = max(S1, [], 2);
S2    = cellfun('size', C, 2);
maxS2 = max(S2, [], 1);
Result2 = zeros(sum(maxS1), sum(maxS2));
c1 = 1;
for i1 = 1:size(C, 1)
    c2 = 1;
   for i2 = 1:size(C, 2)
       X = C{i1, i2};
       Result2(c1:c1 + size(X,1) - 1, c2:c2 + size(X,2) - 1) = X;
       c2 = c2 + maxS2(i2);
   end
   c1 = c1 + maxS1(i1);
end
isequal(Result, Result2)
ans = logical
   1

It took some tome to create some test data as input. Please care for providing some code, which creates your input data, to make answering as easy as possible.