cplex

问题 I use Python API in Cplex to solve a Linear programing problem. When using Cplex, I had the result below: But then I saved my LP prolem as a lp file and use Cplex to solve again, the result was a little bit difference from the first one: Anyone gives an explanation? Below is my function: def SubProblem(myobj,myrow,mysense,myrhs,mylb): c = cplex.Cplex() c.objective.set_sense(c.objective.sense.minimize) c.variables.add(obj = myobj,lb = mylb) c.linear_constraints.add(lin_expr = myrow, senses =

问题 I have one constraint set for(int t = 0; t < NbPeriods; t++){ for (int j =0; j < NbLocations; j++){ IloExpr Ct1(env); for(int u = 0; u < t; u++){ Ct1 += Fortified[u][j]; } model.add(Interdicted[t][j] <= 1 - Ct1); } }​ after some modification I have to remove this constraint set from the model. model.remove() is not working. How can I do it using IloRangeArray protection(env) in this case. 回答1: You need to define you constraints through IloConstraint before adding to the model and save in a

问题 I try to solve a very large optimization problem in R, so I want to install rcplex. I've not much experience with R, so excuse me if I ask stupid things. First I installed cplex studio and rtools40. I've tried to follow the manual https://cran.r-project.org/web/packages/Rcplex/INSTALL. Then I changed the makevars.win file to ifeq "$(WIN)" "64" PKG_LIBS = -L"C:/Program Files/IBM/ILOG/CPLEX_Studio_Community1210/cplex/bin/x64_win64" -lcplex12100 -lm PKG_CPPFLAGS = -D_LP64 -I"C:/Program Files/IBM

问题 I'm trying to compare results from a PLNE model using CPLEX, and I want to use python in order to run this CPLEX model several times and compare the results. How can I run .mod files (those made on CPLEX) in python ? I read stuffs about cplex library on python but, if I understood correctly, it is aimed at making models directly on python... I'm a total noob so any advice would help :) Thank you ! 回答1: the best is to use the doopl package For instance, You may write zootupleset.mod int nbKids

来源： https://stackoverflow.com/questions/63931583/find-next-number-for-sets-in-opl

来源： https://stackoverflow.com/questions/62989416/skip-missing-data-from-table-in-opl-model

问题 I am trying to define a binary decision variable in java using cplex. That's a two dimensional variable. It means that if a path starts from a specific station it should be 1 or otherwise 0. I have a set of station, J and a set of paths, K and my decision variable is Z_jk. Currently I am defining the code like following, but it doesn't work. Could anybody please help me? Thanks in advance. // define variables z = new IloNumVar[stations_start.size()][]; for (int j=0; j<stations_start.size();j+

问题 I am trying to define a binary decision variable in java using cplex. That's a two dimensional variable. It means that if a path starts from a specific station it should be 1 or otherwise 0. I have a set of station, J and a set of paths, K and my decision variable is Z_jk. Currently I am defining the code like following, but it doesn't work. Could anybody please help me? Thanks in advance. // define variables z = new IloNumVar[stations_start.size()][]; for (int j=0; j<stations_start.size();j+

问题 I am trying to use Pulp to setup my LP model and solve it using CPLEX solver. I have CPLEX installed with license on my laptop but getting the below error : PulpSolverError: PuLP: cannot execute cplex.exe 回答1: Make sure that cplex.exe is in your PATH (see Adding directory to PATH Environment Variable in Windows). Alternately, you can set the path argument to the location of cplex.exe in the CPLEX_CMD constructor (see the source code). 来源： https://stackoverflow.com/questions/51275018/unable-to

问题 I am trying to TSP with Lazy constraint callback. From Answer given here and here, I have tried to use the code from the links and was able to add the call back function. Now I am struggling with add_lazy_constraints . Here is my current code: It is a 9 Node TSP. import docplex.mp.model as cpx from cplex.callbacks import LazyConstraintCallback from docplex.mp.callbacks.cb_mixin import * class DOLazyCallback(ConstraintCallbackMixin, LazyConstraintCallback): def __init__(self, env):