Converting optimization output to struct

I am optimising a OtpimizationProblem with the follwoing variables:

SI  = optimvar('SI', 1,       1,       J,N,'Type','integer','Lowerbound',0,'Upperbound',1);
SO  = optimvar('SO', 1,       1,       J,N,'Type','integer','Lowerbound',0,'Upperbound',1);
SD  = optimvar('SD', 1,       1,       KD+J,N,'Type','integer','Lowerbound',0,'Upperbound',1);
X   = optimvar('X',  1,       numel(I),J,N,'Type','integer','Lowerbound',0,'Upperbound',1);
Y   = optimvar('Y',  1,       numel(I),J,N,'Type','integer','Lowerbound',0,'Upperbound',1);
test= optimvar('test',1,      numel(I),J,N,'Type','integer','Lowerbound',0,'Upperbound',1);
Z   = optimvar('Z',  1,       1,       J,N,'Lowerbound',0,'Upperbound',1);
E   = optimvar('E',  1,       1,       J,N,'Lowerbound',0,'Upperbound',1);
W   = optimvar('W',  1,       1,       J,N,'Lowerbound',0,'Upperbound',1);
T   = optimvar('T',  1,       1,       1,N,'Lowerbound',0,'Upperbound',H);
TLB = optimvar('TLB',1,       1,       J,N,'Lowerbound',0);
TEE = optimvar('TEE',1,       1,       J,N,'Lowerbound',0);
TS  = optimvar('TS', 1,       1,       J,N,'Lowerbound',0);
TW  = optimvar('TW', 1,       1,       J,N,'Lowerbound',0);
BS  = optimvar('BS', 1,       numel(I),J,N,'Lowerbound',0);
BE  = optimvar('BE', 1,       numel(I),J,N,'Lowerbound',0);
BP  = optimvar('BP', 1,       numel(I),J,N,'Lowerbound',0);
II  = optimvar('II', numel(M),1,       J,N,'Lowerbound',0);
IO  = optimvar('IO', numel(M),1,       J,N,'Lowerbound',0);
IV  = optimvar('IV', numel(M),1,       K+J,N,'Lowerbound',0);
FVU = optimvar('FVU',  numel(M),K+J,J,N,'Lowerbound',0);
FUV = optimvar('FUV',  numel(M),J,K+J,N,'Lowerbound',0);
FUU = optimvar('FUU',  numel(M),J,J,N,'Lowerbound',0);
FVV = optimvar('FVV',  numel(M),K+J,K+J,N,'Lowerbound',0);
Q   = optimvar('Q',  1,1,numel(R),N,'Lowerbound',0);

In order to optimize the problem I can either use

solve(scheduleprob)

or

SP=prob2struct(scheduleprob);
[sol2,fval2, exitflag2, output2] = intlinprog(SP.f,SP.intcon,SP.Aineq,SP.bineq,...
    SP.Aeq,SP.beq,SP.lb,SP.ub,SP.x0,SP.options)

The first method gives the solution in the following form:

This form is easy to use, and therefor prefferable for me.

The seconde method gives its result as a 4599x1 double.

Is there a way to convert the second type of result into the first type?

I am aware that in this example there is no difference in which method I use, but if I use cplex, which is a lot faster, the results will be presented in the second form.

Answer 1

[Alan Weiss]

You might be interested in the function mapSolution. You need to make the problem structure, but then, given the x output from cplex, it will give you the sol solution structure that you want.

Alan Weiss

MATLAB mathematical toolbox documentation

Answer 2

[Matt J]

I'm a bit surprised that OptimizationProblem class doesn't have a class method for this, but the example below shows how you can over-write an existing sol structure with the pure numeric output from linprog and other similar solvers. The disadvantage is that you have to have a template sol struct already lying around somewhere.

x=optimvar('x',[4,1],'LowerBound',[1:4]*10);
y=optimvar('y',[3,1],'LowerBound',[5:7]*10);

prob=optimproblem;
prob.Objective=sum(x)+sum(y);

sfprob=prob2struct(prob);

xnum=linprog(sfprob)

sol=solve(prob)

sol2=overwrite_sol(sol,xnum) %convert xnum to the same structure form as sol

        function solnew=overwrite_sol(sol,x)
        
            f=fieldnames(sol);
            I=sol;
            c=0;
            for i=1:numel(f)
               I.(f{i})=c+(1:numel(sol.(f{i})));
               c=I.(f{i})(end);
            end
        
            solnew=sol;
            for i=1:numel(f)
               solnew.(f{i})=x(I.(f{i}));
            end
            
end

[Pepijn Baart]

Thank you for your answer. The problem is that I do not have a sol structure to overwrite.

[Matt J]

You can generate one by solving a silly version of the problem with a really simple fake objective and constraints.