How can I convert my matrix of 61 x 1 cells (60 cells of 10 x 1 and 1 cell of 3 x 1) to an array of 603 x 1?

I have a matrix consisting of 61 x 1 cells, with 60 cells of 10 x 1 and 1 cell of 3 x 1. How can I convert it into an array of 603 x 1?

cell2mat does not work as I have 1 cell that is sized differently from the other 60 cells. However, I would need to maintain the size of 603 x 1 as I will need it to match the size of another matrix for correlation purposes.

I really appreciate your help!

[Sriram Tadavarty]

Hi Nehohmee,

cell2mat should be working in this case. Since, all the cells have column vector itself. Try the following:

a = cell(61,1);
a(1:60) = {rand(10,1)};
a(61) = {rand(3,1)};

aM = cell2mat(a);

[nehohmee]

Hi Sriram,

Thank you for your reply.

A problem I have is that my 3 x 1 cell is randomly placed within the 61 number of cells. Is there a way then for me to do cell2mat directly without having to search for the 3 x 1 cell?

[Rik]

Can you post a data example, similar to what Sriram did? I don't clearly see how what you are describing is different from that code.

[nehohmee]

Sorry if I wasn't clear. I have this data (a fragment shown in the image) of different numbers in each cell (10 numbers in each cell). Row 61 is the only cell with 3 x 1. However, the position of this 3 x 1 cell changes as I am shuffling its position amongst these 61 cells every round of my loop. Is there a way for me to utilise cell2mat when my 3 x 1 cell is randomly placed amongst these 61 cells?

My aim is just to obtain a vector of 603 x 1 every round of my loop.

Thank you.

[Sriram Tadavarty]

Yeah. It will just work without any issue. You can try modifying the value of 61 above with some other value, as shown below:

a = cell(61,1);
a(1:61) = {rand(10,1)};
index = randi([1 61],1,1); % Get random index to place 3 x 1 elements
a(index) = {rand(3,1)}; % This 3 x 1 is placed randomly in the 61 cell array

aM = cell2mat(a);

Hope this helps.

[nehohmee]

Thank you for your help!

Answer 1

[Rik]

If you look closer you will see that cell 61 is not 3x1, but 1x3.

%generate sample data
data=cell(61,1);
for n=1:61
    data{n}=n+rand(10,1);
end
data{randi(end)}=rand(1,3);%yes, 1x3 not 3x1, see your screenshot

%linearize every cell that has more than 1 column
for n=( find(cellfun('size',data,2)>1) )'
    data{n}=data{n}(:);
end
%convert to 603x1 vector
a=cell2mat(data);

[nehohmee]

Oh my so that's why it didn't work! Thank you so much for spotting that mistake of mine. Have a great day ahead!

[Rik]

Happy to help. If you feel my answer solved your issue, please consider marking it as accepted answer.