search

coin-or / Clp.old

This a mirror of the subversion repository on COIN-OR.
https://projects.coin-or.org/Clp
Other
36 stars 20 forks source link

[TRAC] HotStart problem with stable/1.14 #39

Open qtothec opened 6 years ago

qtothec commented 6 years ago

Moved from TRAC as part of COIN fORgery: https://projects.coin-or.org/Clp/ticket/54

The attached code reads an LP file, initialSolve(), markHotStart(), change both bounds of variable 11 to 3, solveFromHotStart(), change both bounds of variable 11 to 2, solveFromHotStart().

When printing the status of the optimization, when bounds are 3, the problem is not solved to optimality and iterationLimit is reached, which is quite odd for such a small problem. If the input file is modified, setting the lower bound of var 11 to 3 in the lp file, the three problems are solved to optimality (they all have an optimal value of 49).

It also seems that getIterationCount() always returns 0 when using solveFromHotstart().

bernalde commented 6 years ago

Attachments: https://projects.coin-or.org/Clp/attachment/ticket/54/clp_hotstart.cpp https://projects.coin-or.org/Clp/attachment/ticket/54/hotstart.lp https://projects.coin-or.org/Clp/attachment/ticket/54/output.txt

jjhforrest commented 6 years ago

Unable to reproduce with trunk