Undefined function or variable 'optimproblem'
显示 更早的评论
Hi; please I try to run the program of " Cutting Stock Problem: Problem-Based " to understand column generation algorithm , but I had this error "Undefined function or variable 'optimproblem'", you find below the program:
logLength = 40;
lengthlist = [8; 12; 16; 20];
quantity = [90; 111; 55; 30];
nLengths = length(lengthlist);
patterns = diag(floor(logLength./lengthlist));
nPatterns = size(patterns,2);
subproblem = optimproblem();
cuts = optimvar('cuts', nLengths, 1, 'Type','integer','LowerBound',zeros(nLengths,1));
subproblem.Constraints = dot(lengthlist,cuts) <= logLength;
lpopts = optimoptions('linprog','Display','off');
ipopts = optimoptions('intlinprog',lpopts);
reducedCost = -inf;
reducedCostTolerance = -0.0001;
exitflag = 1;
while reducedCost < reducedCostTolerance && exitflag > 0
logprob = optimproblem('Description','Cut Logs');
% Create variables representing the number of each pattern used
x = optimvar('x', nPatterns, 1, 'LowerBound', 0);
% The objective is the number of logs used
logprob.Objective.logsUsed = sum(x);
% The constraint is that the cuts satisfy the demand
logprob.Constraints.Demand = patterns*x >= quantity;
[values,nLogs,exitflag,~,lambda] = solve(logprob,'options',lpopts);
if exitflag > 0
fprintf('Using %g logs\n',nLogs);
% Now generate a new pattern, if possible
subproblem.Objective = 1.0 - dot(lambda.Constraints.Demand,cuts);
[values,reducedCost,pexitflag] = solve(subproblem,'options',ipopts);
newpattern = round(values.cuts);
if double(pexitflag) > 0 && reducedCost < reducedCostTolerance
patterns = [patterns newpattern];
nPatterns = nPatterns + 1;
end
end
end
if exitflag <= 0
disp('Error in column generation phase')
else
x.Type = 'integer';
[values,logsUsed,exitflag] = solve(logprob,'options',ipopts);
if double(exitflag) > 0
values.x = round(values.x); % in case some values were not exactly integers
logsUsed = sum(values.x);
fprintf('Optimal solution uses %g logs\n', logsUsed);
totalwaste = sum((patterns*values.x - quantity).*lengthlist); % waste due to overproduction
for j = 1:size(values.x)
if values.x(j) > 0
fprintf('Cut %g logs with pattern\n',values.x(j));
for w = 1:size(patterns,1)
if patterns(w,j) > 0
fprintf(' %g cut(s) of length %d\n', patterns(w,j),lengthlist(w));
end
end
wastej = logLength - dot(patterns(:,j),lengthlist); % waste due to pattern inefficiency
totalwaste = totalwaste + wastej;
fprintf(' Waste of this pattern is %g\n',wastej);
end
end
fprintf('Total waste in this problem is %g.\n',totalwaste);
else
disp('Error in final optimization')
end
end
回答（1 个）
Alan Weiss
2018-10-22
0 个投票
As the release notes show, optimproblem was introduced in R2017b. Or you can find out this information at the bottom of the optimproblem function reference page.
Alan Weiss
MATLAB mathematical toolbox documentation
类别
在 帮助中心 和 File Exchange 中查找有关 Linear Programming and Mixed-Integer Linear Programming 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
