I can convert a cell array of matrices to matrix:
>> C={[1,1]; [2,2]; [3,3]};
>> cell2mat(C)
ans =
1 1
2 2
3 3
This is OK. But, I want to convert a cell array including other cell arrays to a matrix:
>> C={{1,1}; {2,2}; {3,3}};
>> cell2mat(C)
Error using cell2mat (line 53)
Cannot support cell arrays containing cell arrays or objects.
So, desired output is:
>> mycell2mat({{1,1}; {2,2}; {3,3}})
ans =
1 1
2 2
3 3
How to do this?
I want to do same thing for multidimensional ones also:
>> mycell2mat({{1,1;1,1}; {2,2;2,2}; {3,3;3,3}})
ans(:,:,1) =
1 1
1 1
ans(:,:,2) =
2 2
2 2
ans(:,:,3) =
3 3
3 3
To be honest, I never liked cell2mat
for being slow, so I've come up an alternative solution using comma-separated lists instead!
This is fairly simple, just use the colon operator and concatenate all vectors vertically:
C = {[1,1]; [2,2]; [3,3]};
A = vertcat(C{:})
and so we get:
A =
1 1
2 2
3 3
This is a bit trickier. Since it's a cell array of cell arrays, we'll have to obtain a vector of all elements by a double use of the colon and horzcat
, and then reshape
it into the desired matrix.
C = {{1,1}; {2,2}; {3,3}};
V = [size(C{1}), 1]; V(find(V == 1, 1)) = numel(C);
A = reshape([horzcat(C{:}){:}], V)
and so we get:
A =
1 1
2 2
3 3
The manipulation of V
makes sure that A
is reshaped correctly without having to specify the output dimensions explicitly (unfortunately, I didn't find a one liner for this). This also works for multi-dimensional cell arrays as well:
C = {{1, 1; 1, 1}; {2, 2; 2, 2}; {3, 3; 3, 3}};
V = [size(C{1}), 1]; V(find(V == 1, 1)) = numel(C);
A = reshape([horzcat(C{:}){:}], V)
A(:,:,1) =
1 1
1 1
A(:,:,2) =
2 2
2 2
A(:,:,3) =
3 3
3 3
I think the correct result for the last example should be a 6-by-2 matrix instead of a 2-by-2-by-3. However, that is not what you requested, so it's off-topic.
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