George
Posts:
13
Registered:
8/19/10


Matrix replication
Posted:
Oct 31, 2013 5:35 PM


Hi all,
Here is a simple code in which a given matrix is replicated in five different ways:
% Matrix to be replicated b=100*rand(12,12,2000); % 1 tic Id1 = (1 : size(b,1))'; Id2 = (1 : size(b,2))'; Id3 = (1 : size(b,3))'; Id4 = (1 : size(b,4))'; x1=b(Id1(:,ones(1,1)), Id2(:,ones(1,1)), Id3(:,ones(1,1)),... Id4(:,ones(50),1)); toc clear x1 % 2 tic x2 = bsxfun(@plus, zeros(1,1,1,50), b); toc clear x2 % 3 tic x3 = bsxfun(@times, ones(1,1,1,50), b); toc clear x3 % 4 tic x4=repmat(b,[1 1 1 50]); toc clear x4 % 5 tic x5=reparray(b,[1 1 1 50]); toc clear x5
Is anybody aware of another way to replicate matrices faster than the above? Or is there any possibility to improve appropriately any of the above methods to run faster? Thank you in advance.
George Papazafeiropoulos

