Vectorizing interdependent nested 4-for loop

1 view (last 30 days)
ingstalam
ingstalam on 12 Jan 2015
Edited: ingstalam on 12 Jan 2015
How to speed up this piece of code? How to vectorise this code? Is no other way possible?
for i1=1:num_agents % for all i
for rows=1:num_tasks*num_parts-1 % for all m_i,n_i in E_i
for ell=1:gL-G(rows,rows+1,i1) % for all ell
for i2=1:num_agents
xtemp = clearer;
% half-sum 1st part
for s = ell:gL%-G(rows,rows+1,i1)
if mod(rows,num_tasks)~=0
xtemp(i1,ceil(rows/num_tasks),mod(rows,num_tasks),s) = 1;
elseif mod(rows,num_tasks)==0
xtemp(i1,ceil(rows/num_tasks),num_tasks,s) = 1;
end
end
% half-sum 2nd part
for s = 1:ell+G(rows,rows+1,i1)-1
if s <= gL
if mod(rows,num_tasks)~=0
xtemp(i2,ceil(rows/num_tasks),mod(rows,num_tasks)+1,s) = 1;
elseif mod(rows,num_tasks)==0
xtemp(i2,ceil(rows/num_tasks)+1,1,s) = 1;
end
end
end
xtemp = xtemp(:);
Aineq(counter,:) = xtemp';
bineq(counter) = 1;
counter = counter + 1;
end
end
end
end

Answers (1)

Rick Rosson
Rick Rosson on 12 Jan 2015
  1. Did you pre-allocate Aineq prior to the loop?
  2. Did you pre-allocate bineq prior to the loop?
  2 Comments
ingstalam
ingstalam on 12 Jan 2015
Yup.
Aineq = spalloc(J*K+J*K+I*ELL+I*I*gL*(J*K-1),matwid,3*I*J*K*ELL+I*I*gL*(J*K-1)*(G_max)); % Allocate Aineq
bineq = zeros(J*K+J*K+I*ELL+I*I*gL*(J*K-1),1); % Allocate bineq
ingstalam
ingstalam on 12 Jan 2015
Edited: ingstalam on 12 Jan 2015
In fact i used sparse matrix allocation to speed up the results.

Sign in to comment.

Products

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!