How do I add a column to an existing matrix?

Hi I have this code here:

[m,n] = size(windows);
H = zeros(n,1);
for i = 1:n
    r = windows(:,i);
    H(i) = dfaedit(r,1,1,1);
end

Richt now it creates a new variable H. However, every time I run this code, I would like it to add the resulting column to an existing variable H_all so that it results in a matrix of columns.

Does that make sense? Help is much appreciated!

Answer 1

[Cris LaPierre]

Use [] to concatenate your result to your existing variable. You'll need to force your for loop to create a column vector instead of a row vector (change shown below).

Note that this assumes that H_all will always have the same number of rows as H.

[m,n] = size(windows);
H = zeros(n,1);
for i = 1:n
    r = windows(:,i);
    H(i,1) = dfaedit(r,1,1,1);
end
H_all = [H_all,H]

[lil brain]

Perfect! One last question. How would I need to write this if I dont want a new variable created every time? Thanks!

[Cris LaPierre]

Meaning you just want to add to H_all directly? Specify the column of H_all to add the new data to.

[m,n] = size(windows);
c = size(H_all,2)+1;
for i = 1:n
    r = windows(:,i);
    H_all(i,c) = dfaedit(r,1,1,1);
end