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How can I merge many rows of different lengths into a matrix?

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Hi everyone! I encountered a problem in merging many rows of different lengths into a matrix, for example,
A=[1:2];
B=[3:7];
C=[1:10];
What I want to achieve is to have the following matrix:
D=[A;B;C]
% which does not work
% to be in the format of following
D=[1,2,0,0,0,0,0,0,0,0;
3,4,5,6,7,0,0,0,0,0;
1,2,3,4,5,6,7,8,9,10]
Does any one have a good way of filling zeros? The speed is also a concern as such operations would be repeated for millions of times .
Any help would be appreciated!

Accepted Answer

Stephen23
Stephen23 on 14 Dec 2018
>> C = {1:2,3:7,1:10};
>> L = cellfun('length',C);
>> M = zeros(numel(C),max(L));
>> for k = 1:numel(C), M(k,1:L(k)) = C{k}; end
>> M
M =
1 2 0 0 0 0 0 0 0 0
3 4 5 6 7 0 0 0 0 0
1 2 3 4 5 6 7 8 9 10

More Answers (1)

Omer Yasin Birey
Omer Yasin Birey on 14 Dec 2018
Hi Rupeng, as far as I understand you want to work with arrays. So you can use this code below
A=[1:2];
B=[3:7];
C=[1:10];
dimAdjustforA = max(max(length(A),length(B)),length(C))-length(A);%you have to set the dimension
A = [A zeros(dimAdjustforA,1)'];
dimAdjustforB = length(A)-length(B)%again to make it same dimension with the maximum one
B = [B zeros(dimAdjustforB,1)'];
D = [A;B;C]

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