How to convert a vector into a matrix using reshape ,but what should be the size that should be specified?

I have converted a matrix A into a vector v and performed certain operations on the vector v and obtain a new vector G which have less number of elements compared to vector v.Now I want to convert this vector g into a matrix?But I dont know what must be the size that should be specified while using reshape.

Answer 1

[James Tursa]

If it has fewer elements than originally, you can't directly reshape it into the same size original matrix. You could pad with 0's or NaN's if that works for your downstream processing. E.g.,

n = numel(v); % Number of original elements
G(end+1:n) = NaN; % Pad with NaN's
B = reshape(G,size(A)); % Reshape back to original size

If that doesn't work for you, then you will need to give us more details about what you will be doing with the reshaped G vector downstream in your code. Then we can offer suggestions.