Rewriting a value with a loop

Hello,

I would like to rewrite a value in Matlab using a loop. The value vl (20x601) should be rewritten so only the rows written in hright (15 rows instead of the original 20) are used.

I tried the following, but this constantly rewrites vlnew making all rows the same.

for i = hright for j = 1:length(hright) vlnew(j,:)=vl(i,:); end end

Does anyone have a suggestion how to do this? Thank you in advance.

Answer 1

[Jos (10584)]

    VL = bsxfun(@plus,(1:9).',[10 20 30]) % some example data

    RowsToSelect = [1 3 4 7]
    VLnew = VL(RowsToSelect,:)

    % or with a for-loop, which is much slower and is going against 
    % the reason why you want to use matlab in the first place ... 
    for k = 1:numel(RowsToSelect)
       VLnew2(k,:) = VL(RowsToSelect(k),:) ;
    end

[Dennis]

That works great! Thanks a lot for your help.

[Jos (10584)]

You're welcome. Not that you can multi-select and switch using the indexing trick quite easily. This really shows the power of matlab!

A = [11 12 ; 21 22 ; 31 32 ; 41 42] 
idx = [4 1 2 2 2] % row indices
B = A(idx,:) % selection