scip

SCIP write best feasible solution in automated test

由 末鹿安然 提交于 2019-12-11 18:08:10
问题 Based on steps in http://scip.zib.de/doc/html/TEST.php, I have managed to set up an automated test using SCIP. However, I'd like to write the solution (best feasible solution) to a file, instead of just getting the objective value. Is there anyway to do it in the automated test? I did a hack in check.sh by replacing OPTCOMMAND=optimize; write solution myfilename.sol; But too bad, it doesn't seem to work, when I tried to make TEST=mytest test, this line is observed from the output bash ./check

Dual bound change event type?

由 时光怂恿深爱的人放手 提交于 2019-12-11 18:05:59
问题 I'm trying to code a simple event handler that does certain things whenever the best primal or dual bounds change (please let me know if I'm reinventing the wheel here and there is already a way of doing this). For the primal bound I can catch the SCIP_EVENTTYPE_BESTSOLFOUND event, but for dual bound I can't seem to find an appropiate event type (in type_event.h ). All the bound-related events I see seem to be for variable bounds. Am I missing something? Or should I just use something like

What do the events that `SCIP_EVENTTYPE_NODESOLVED` comprises mean?

由 浪子不回头ぞ 提交于 2019-12-11 15:50:36
问题 I'm trying to catch a change in the dual bound using an event handler. There is no event in type_event.h for catching this, so I want to use the SCIP_EVENTTYPE_NODEFEASIBLE event. I'm a bit confused by the relationship between the events that SCIP_EVENTTYPE_NODESOLVED is comprised of ( SCIP_EVENTTYPE_NODEFEASIBLE , SCIP_EVENTTYPE_NODEINFEASIBLE , and SCIP_EVENTTYPE_NODEBRANCHED ). Are these events disjoint? What do they mean specifically? IMHO, the documentation is not very clear about this.

LP relaxation in SCIP

由 梦想的初衷 提交于 2019-12-11 08:28:59
问题 I'm trying to solve a MIP using the SCIP command line, with the problem input in CPLEX LP format. However, due to large number of variables, the optimization is taking a lot of time. Is there some way to compute the LP Relaxtion solution of the same MIP in SCIP? Or any other way to get an approximate, somewhat suboptimal solution? 回答1: If you are just interested in the LP relaxation you should try to use SoPlex to solve your problem. If you want to limit the computation time in SCIP you can

SCIP Python Installation Issue Windows with pip

由 一曲冷凌霜 提交于 2019-12-11 04:46:28
问题 Hello community / developers, I am currently trying to install SCIP with python and found that there is Windows Support and a pip installer based on https://github.com/SCIP-Interfaces/PySCIPOpt/blob/master/INSTALL.md. Nevertheless I run into a problem "Cannot open include file" Below is a list of the things I performed to get to this step. Download Python Anaconda 2.7 64 bit Install with all checkboxes as they are Download PyCharm Community edition Click 64 bit desktop link, and associate

SCIP Customized settings not loaded

由 [亡魂溺海] 提交于 2019-12-07 12:23:09
问题 I have defined customized settings in a file called scip.set and put in in myscipdir/settings. The settings contain limits/time = 86400 limit/memory = 61440 lp/threads = 6 However, SCIP doesn't seems to load the customized settings, instead, default settings are used (see attached picture), and the parameter file is not found under /check/results directory. May I know what is the correct way to do this? I can set both time and memory limits from make test command line, but I'd also need to

lapack library for scip optimization

由 佐手、 提交于 2019-12-06 22:07:53
I have a quadratic optimization problem with linear constraints that I want to solve using SCIP . The optimization matrix that I want to be minimized is positive semi-definite (it is the variance of certain variables, to be precise). I have the problem in a file in CPLEX LP format and when I optimize in SCIP , I get the message Quadratic constraint handler does not have LAPACK for eigenvalue computation. Will assume that matrices (with size > 2x2) are indefinite. So SCIP starts optimization assuming that the matrix is indefinite and takes a large amount of time. I have installed LAPACK and

Install SCIP on Eclipse

由 谁说我不能喝 提交于 2019-12-02 18:01:10
问题 I am trying to make the SCIP work with Java/Windows 7. I have installed Eclipse Mars. I am kind of new to the SCIP. I read through the installation procedure and try to install the SCIP. But I can't understand the installation procedure clearly. I downloaded this library, and installed the .jar and the .dll like I am used to do, however there are very few examples online about SCIP in Java, and I can't import this correctly. Can anyone tell me how to install the SCIP or guide me to an example

Install SCIP on Eclipse

由 泄露秘密 提交于 2019-12-02 11:19:58
I am trying to make the SCIP work with Java/Windows 7. I have installed Eclipse Mars. I am kind of new to the SCIP. I read through the installation procedure and try to install the SCIP. But I can't understand the installation procedure clearly. I downloaded this library, and installed the .jar and the .dll like I am used to do, however there are very few examples online about SCIP in Java, and I can't import this correctly. Can anyone tell me how to install the SCIP or guide me to an example? Thank you very much. There was an issue with the file names in the JNI library. I fixed this issue

What happens when I modified the RHS of a constraint (GLPK)?

由 亡梦爱人 提交于 2019-12-01 13:20:58
I am increasing the RHS of less-than-or-equal constraint of a MIP problem with GLPK. However, sometimes, after re-optimizing, GLPK cannot find any feasible solution within the time limit. So I am guessing it does not check if the previous solution was feasible. Does anybody have any experience with that? Or can point me to a document that is not the source code itself? Also, I would like to know what is the workflow after I add a constraint for any other solver (e.g. Gurobi, Cplex, SCIP, CBC) so any information is helpful. Cheers! After changing something in the model, all solving information
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