Creating vector of all numbers in a cell array.

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];

Answer 1

[Honglei Chen]

You can do

AContents = [A{:}]

Answer 2

[Andrei Bobrov]

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{:});

Answer 3

[Jan]

[{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.