Converting a 3D Matrix to multiple 2D matrices
1 次查看(过去 30 天)
显示 更早的评论
I have a 3D matrix, 1000 x 1000 x 40
I want to convert this matrix to 40 different matrices, 1000 x 1000 each. I suppose I am asking for the inverse of repmat, however searches into that have not led to progress.
Any help is appreciated.
2 个评论
Athrey Ranjith Krishnanunni
2021-1-17
编辑:Athrey Ranjith Krishnanunni
2021-1-17
Something like this?
largeMatrix = randn(1000,1000,40);
smallMatrixArray = cell(40,1);
for iOuterDim = 1:40
smallMatrixArray{iOuterDim} = largeMatrix(:,:,iOuterDim);
end
Steven Lord
2021-1-17
I want to convert this matrix to 40 different matrices
Why? What benefit do you hope to gain by doing that instead of indexing into the array to retrieve the appropriate slice when needed?
A = reshape(1:(3*4*5), [3 4 5]);
A4 = A(:, :, 4)
What happens when or if you expand your problem sizes to an array of size 10000 in the third dimension? Your workspace would become awfully cluttered with ten thousand and one arrays in it.
采纳的回答
Bruno Luong
2021-1-17
编辑:Bruno Luong
2021-1-17
Assuming A is array 1000 x 1000 x 40
C = num2cell(A,[1 2]);
2 个评论
Athrey Ranjith Krishnanunni
2021-1-17
You'll have to write
C = shiftdim(num2cell(A,[1 2]));
to get rid of the leading singleton dimensions, though.
Bruno Luong
2021-1-17
Well it is nicer but it is not requirement by OP.
C{k} still give the the kth matrix as requested.
更多回答(0 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Logical 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!