Creating vector of all numbers in a cell array.

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This is probably an easy solution, but I cannot figure it out.
I have an m x m cell array where each cell contains a 1 x n vector of numbers. I would like to create a new array that is simply a list of all of the numbers in the cell array (not necessarily unique).
So a simple case (not m x m):
A = {1; [1 2]; [1 2 3 4 5]};
Result:
AContents = [1 1 2 1 2 3 4 5];

Accepted Answer

Honglei Chen
Honglei Chen on 6 Jul 2012
You can do
AContents = [A{:}]

More Answers (2)

Andrei Bobrov
Andrei Bobrov on 6 Jul 2012
Edited: Andrei Bobrov on 6 Jul 2012
nums = cat(2,A{:});
general case:
let
A = arrayfun(@(x)randi(randi([3 40]),randi([6 20],1,2)),zeros(3,4),'un',0);
solution
outc = cellfun(@(x)x(:),A,'un',0);
out = cat(1,outc{:});

Jan
Jan on 7 Jul 2012
[{A{:}] and cat(2, A{:}) seem to have a weak pre-allocation, such that the processing time grows super-linear with the data size. If you process large cells, e.g. a {1 x 100} cell, which contains [1 x 10] doubles, the function Fex: Cell2Vec.mex can be 3 times faster.

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