cell to matrix conversion with a slight modification

2019 7 30
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更新时间：2019 7 31
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I have a 1×501 cell array(named C). Each element in the cell is a 4*4 matrix, which means I have 501 matrices of 4*4 dimensions. What I have to do is: for each matrix in the cell, all the elements in the particular matrix must be put in 1 row.
for example I have to convert
[1,2,3,4 [0,1,0,0
5,6,7,8 1,0,0,0 ..........so one upto 501 matrices
9,10,11,12 0,0,1,1
13,14,15,16] 0,0,0,1]
into
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,
0,1,0,0,1,0,0,0,0,0,1,1,0,0,0,1
.............
........
so on upto 501 rows. ]
Help if possible.

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Guillaume
Guillaume 2019-7-30

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Assuming that you mean a 501x16 matrix, then:
m = reshape(cat(3, yourcellarray{:}), [], numel(yourcellarray)).'
This concatenate the 501 matrices into a 4x4x501 matirx array, reshape that into a 16x501 matrix where each column is a flattened matrix and then transpose into a 501x16 matrix.

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hrushikesh kyathari
编辑：hrushikesh kyathari 2019-7-31
Thanks for the reply, but I guess I didn't explain my question properly which led to miscomprehension. I editted it, could you please look into it again.
Guillaume
Guillaume 2019-7-31
编辑：Guillaume 2019-7-31
Your edit is exactly what my code does except that since matlab is column major, the matrix
[1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16]
gets reshaped into
[1 5 9 13 2 6 10 14 3 7 11 15 4 8 12 16]
If the order does really matter then you ought to work with columns rather than rows as that would avoid a lot of expensive (in term of time) transpositions / permutations, but this will do:
m = reshape(permute(cat(3, yourcellarray{:}), [3, 2, 1]), numel(yourcellarray), [])
Thanks a lot, I actually did a silly mistake as I copied your 1st answer but gave the output as my original cell .My bad, sorry for that.
The order does matter for me, I need the order to be as [1,2,3,5,6,7,9,10,11,4,8,12]
I actually don't need the last row. I would be pleased if you could help me here.
Guillaume
Guillaume 2019-7-31
If by last row, you mean the last cell of the cell array, then just delete it before the conversion, or:
m = reshape(permute(cat(3, yourcellarray{1:end-1}), [3, 2, 1]), numel(yourcellarray)-1, [])
no, I meant the last row of each matrix, so if a matrix is
[1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16]
I need it to be made as [1,2,3,5,6,7,9,10,11,4,8,12]. So I want to apply this to all the matrices
So this would result in final outcome as 501*12 martix.
Guillaume
Guillaume 2019-7-31
Well, then simply remove the last 4 columns from the output
croppedm = m(:, 1:end-4);
or you can do:
m = cat(3, yourcellarray{:})
m = reshape(permute(m(1:end-1, :, :), [3, 2, 1]), numel(yourcellarray), [])

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