How can I convert 2 column matrix to a cell array?
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Is there a convenient way to convert a 2 column matrix into a cell array (without using nested for loops if possible)?
The matrix looks like:
Can I make a matrix from the above matrix such that the rows and columns of the new matrix(or a cell array you can say) will be like you see below:
the empty cells can be NAN and the filled cells are the values of the 3rd column of the old matrix.
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채택된 답변
Walter Roberson
2019년 12월 30일
result = accumarray(matrix(:,[2 1]), matrix(:,3), [], @(v) {v}, {nan})
However I wonder if you would be better off using
result = sparse(matrix(:,2), matrix(:,1), matrix(:,3))
which would be a sparse numeric array instead of a cell array that takes up about 108 bytes per entry.
댓글 수: 3
Andrei Bobrov
2019년 12월 30일
[i,g] = findgroups(matrix(:,2));
out = flip(accumarray([matrix(:,1),i],matrix(:,3)),1);
추가 답변 (2개)
Andrei Bobrov
2019년 12월 31일
T = readtable('path\to\your\xls\file\matrix.xlsx','ReadVariableNames',0);
T.Var3 = str2double(T.Var3);
T = T(any(T{:,1:2} ~= 0,2),:);
M = T{:,:};
[i,g] = findgroups(M(:,2));
out = flip(accumarray([M(:,1),i],M(:,3)),1);
댓글 수: 3
Andrei Bobrov
2019년 12월 31일
T = readtable('C:\Octavework\forums\xls\matrix_v2.xlsx','Range','A:C','ReadVariableNames',0);
T.Var3 = str2double(T.Var3);
T = T(any(T{:,1:2} ~= 0,2),:);
M = T{:,:};
i = findgroups(M(:,2));
out = flip(accumarray([M(:,1),i],M(:,3)),1);
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