Making matrices of different dimensions and clubbing them together

I am running a for loop which gives row matrices as the output.

for (i=1), output matrix is a [1*1114] matrix.

for (i=2), output matrix is a [1*1213] matrix

the dimensions of the matrices keep increasing.

my desired final matrix is a matrix that contains all the stored values of all iterations.

Please help.

Error says : Unable to perform assignment because the size of the left side is 1-by-1114 and the size of the right side is 1-by-1213.

I am new to matlab.

Answer 1

[Stephen23]

A simple and efficient approach using a cell array:

N = number of loop iterations
C = cell(1,N);
for k = 1:N
    ... your code
    C{k} = [...] % output vector
end
V = [C{:}] % output vectors concatenated into one

See:

https://www.mathworks.com/help/matlab/matlab_prog/comma-separated-lists.html

https://www.mathworks.com/matlabcentral/answers/320713-how-to-operate-on-comma-separated-lists

[shahzer rahman]

This works fine if the number of columns in each loop is same. But it doesn't workout when the number of columns is increasing in every loop.

Remember the error: Unable to perform assignment because the size of the left side is 1-by-1114 and the size of the right side is 1-by-1213.

Loop 1 makes a 1-by-1114 matrix. The updated matrix after the second iteration should be a 1-by-1213 matrix. Hence, reassigning the 1-by-1114 matrix to 1-by-1213 matrix looks troublesome.

[Stephen23]

"This works fine if the number of columns in each loop is same."

and also when the number of columns changes.

But it doesn't workout when the number of columns is increasing in every loop."

It worked without error when I tested it (did you try it yourself?):

N = 5
C = cell(1,N);
for k = 1:N
    X = k*ones(1,k); % varying number columns!
    C{k} = X; % output vector
end
V = [C{:}] % concatenate horizontally

Giving:

V =
   1   2   2   3   3   3   4   4   4   4   5   5   5   5   5

If you want them concatenated vertically then download Jos's excellent padcat and use it lke this:

   V = padcat(C{:});

[shahzer rahman]

I didn't define this line properly.

X = k*ones(1,k); % varying number columns!

It works fine now.

Thanks a lot Man. Love you.

[shahzer rahman]

Hey Stephen. Need some more help, man. I am trying to plot each cell values. How do I do that?

Rememeber each cell has a row matrix.

[Stephen23]

P = [cellfun(@(v)1:numel(v),C,'uni',0); C];
plot(P{:})

Answer 2

[Mario Malic]

You can use

A (i, 1:length(output_matrix)) = your data

[shahzer rahman]

Didn't work for my code. But thanks for the help. appreciate it.