Forum Discussion
Why does Xpress ignore my warm start lp solution?
I am trying to use a warm start of the newton barrier method using the example provided here. However, instead of using my supplied solution the solver starts with all values set to 0. I have tried ...
I am afraid your testprob.lp is too simple to tell anything. Without presolve it works as expected. With presolve enabled the problem is solved in presolve, i.e., in presolve all columns are fixed and there is nothing left to do for barrier. In other words, barrier starts with a model that has 0 rows and cols. In this case it will of course not use your starting solution but just stop. The optimal solution is already found before barrier even starts, that is why x0 and x1 differ.
In any case, when using the starting the solution, you should see a line like
Using primal warmstartin the output. Do you see this line?
Could you share your bigger LP? If you don't want to share it here, you may send to danieljunglas(at)fico(dot)com.
