Expand vectors of matrix, but a different number of times each vector
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
Hi all,
I have the following problem. Consider a matrix of the form
Z =[1 0 0 0; 1 0 0 0; 1 0 0 0; 0 0 0 1; 0 0 0 1];
Because I'll use this later, consider the vector that sums the elements of the matrix by rows:
C=[3 0 0 2];
I would like to take every column in Z and expand it according to the elements in C, when the expansion when C=0 is just the column itself, to get
D=[1 1 1 0 0 0 0; 1 1 1 0 0 0 0;1 1 1 0 0 0 0;0 0 0 0 0 1 1;0 0 0 0 0 1 1];
Some things to consider. I have a lot of matrices "Z". In particular, they are defined in a structure way. This means that, for example, I have mk(i).Z where i goes from 1 to, say, 50. This means that I also have 50 vectors "C" (mk(i).C). Finally, the Z's have different dimensions that I don't know ex-ante (they are generated randomly within the code).
Any help would be great, thanks
Fernando
0 Kommentare
Akzeptierte Antwort
Sean de Wolski
am 9 Mai 2012
z2 = cell2mat(cellfun(@(z,c)repmat(z,1,max(c,1)),num2cell(Z,1),num2cell(C),'uni',false))
Not sure why you need to do this though. It's going to take more memory to not get you any more information. If you could explain a little more, we might be able to help with a better way.
Weitere Antworten (1)
Andrei Bobrov
am 9 Mai 2012
C=[3 0 0 2];
D = arrayfun(@(x)[zeros(x==0),ones(x)],C,'un',0);
D = blkdiag(D{:});
D = D(any(D,2),:);
or
D = cell2mat(arrayfun(@(ii)Z(:,ii)*ones(1,C(ii)+(C(ii)==0)),1:numel(C),'un',0));
Siehe auch
Kategorien
Mehr zu Matrix Indexing finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!