Initial data warm start

[Dilan Gmn]

Hey!

I want to use a warm start, but to do this i need to give initial values to my variables. I do not know how to do this in AIMMS?

Does someone know where I need to fill in my initial values?

Regards

[Marcel Hunting]

Hi,

If x(i) is a variable for which you want to give an initial value p(i) then you can write

   x(i) := p(i);

before the solve statement.

Best regards,

Marcel Hunting

AIMMS Optimization Specialist

[Dilan Gmn]

Hey,

This is done in the folder MainExecution right? It looks like the following

x(i) := p(i);

solve OptimalSchedule;

if( OptimalSchedule.ProgramStatus <> 'Optimal')then

empty costfunction;

endif;

Thanks

Op dinsdag 26 juli 2016 12:19:20 UTC+2 schreef Marcel Hunting:

[Marcel Hunting]

That is correct; in the procedure with the solve statement (which appears to be MainExecution is your case).

Marcel

[Dilan Gmn]

Hey Marcel,

I have written a program to solve a scheduling problem. For this problem I am given 2 data sets which I solve separately. 

To obtain a better solution I combine both data sets and the solutions of both data sets. I use the combined solutions as initial data for a warm start to avoid a long running time. 

I have initial data for each variable: p1(i,j,k), p2(j,l,k), p3(j,k), p4(j,k), p5(j), p6(j). The MainExecution looks as follows

p3(j,k) := q3(j,k);

p4(j,k) := q4(j,k);

p5(j) := q5(j);

p6(j) := q6(j);

solve OptimalSchedule;

if( OptimalSchedule.ProgramStatus <> 'Optimal')then

empty costfunction, p1(i,j,k), p2(j,l,k) ;

endif;

Do you know how to transfer the data for the variables p1(i,j,k) and p2(j,l,k) from excel to AIMMS (because I only know how to do this with the other variables)?

When I solve the problem, using initial data for each variable except p1(i,j,k) and p2(j,l,k), the solution gets worse and I get warnings for duplicated rows. Has this something to do with the reason that I did not give initial values for each variable? 

Regards

Op dinsdag 16 augustus 2016 17:40:28 UTC+2 schreef Marcel Hunting:

[Marcel Hunting]

Hi,

You can find several examples on our website that demonstrate how to pass data from Excel to AIMMS, for example the Tea Consumption example.

The warnings for duplicated rows are not related to initial variable values.

Best regards,

Marcel