# Problem with vertically Concatenating vectors in a function

2 views (last 30 days)
Joel Schelander on 27 Apr 2021
Commented: Joel Schelander on 28 Apr 2021
I have a cell array ABC containing three cells each cell contains a 1x1000 double. What I want is to put every double on top of each other in a column vector (nx1).
ABC={1x1000 cell
1x992 cell
1x928 cell);
My function looks like this:
nr=3;
s=1000;
[D]=func(nr,ABC,s);
function D = func(nr,ABC,s)
D = [];
for y =1:nr
data_length = length(ABC{y});
for o = 1:data_length
G((o-1)*s+1:o*s) = [ABC{y}{o} zeros(1,s-length(ABC{y}{o}))].';
end
D = [D; G.'];
end
end
My output should be D=2920000x1 double
But my output now is D=3000000x1 double

Stephen23 on 28 Apr 2021
Edited: Stephen23 on 28 Apr 2021
Rather than using a loop, a much better use of MATLAB would be to use comma-separated lists:
For example:
out = cellfun(@(a)a(:),[ABC{:}],'uni',0);
out = vertcat(out{:})
Or
out = [ABC{:}];
out = [out{:}].'
##### 2 CommentsShowHide 1 older comment
Joel Schelander on 28 Apr 2021
Ye its not sorry. Cell 3 looks like this
AAG{3,1}=1x757 double 1x726 double 1x761 double 1x785 double...]
The thing is that each of the doubles have a representing value in another cell array.
AAI{3,1}=[8 11 8 11...]
What I really want to achieve is to plot AAI against AAG.. Thus I need to repeat the values of AAI so that it corresponds to the doubles in AAG.

DGM on 27 Apr 2021
% a cell array of numeric row vectors
A = {1:3,10:14,1:5}
% all row vectors concatenated into a col vector
bigcolvec = [A{:}]'
gives
A =
1×3 cell array
{1×3 double} {1×5 double} {1×5 double}
bigcolvec =
1
2
3
10
11
12
13
14
1
2
3
4
5
Joel Schelander on 28 Apr 2021
Now the vectos from the cells cant be concatenated:
Error using vertcat
Dimensions of arrays being concatenated are not consistent.

R2019b

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