Converting to a square matrix

In `MATLAB`, say that we have a matrix with the following dimensions:

    [11036,1]

How can we convert that to a square matrix?

Thanks.

Answer 1

[Jos (10584)]

N = numel(MyMatrix) 
N2 = ceil(sqrt(N))
if N2^2 > N
  MyMatrix(N2^2) = 0 % pads with zeros if needed
end
MyMatrix = reshape(MyMatrix,N2,N2) % square!

[med-sweng]

Thanks a lot Jos. Very nice answer!

Answer 2

[Image Analyst]

Since sqrt(11036) is not an integer, are you okay with clipping off some elements?

aNew = a(1:(105*105)); % Extract the proper number of elements.
aNew = reshape(a, [105, 105]);  % Make 2D square.

[med-sweng]

Thanks for your reply. Isn't there an automatic way to do that? And, can padding by "0" for instance be done for filling the empty elements?

[Image Analyst]

Yes, looks like Jos answered before I could. I'm not sure if you knew in advance that the matrix could not be square when you asked, but if you did, you could have gotten a quicker answer if you had specified whether to clip or pad in your original question. I assumed the clipping option when you evidently wanted the padding option. I guess I could have guessed at both ways but it would be better if you just state all your requirements up front so we don't have to guess.