Manuel Fernandez de Dios

  • Gurobi-versary
  • Conversationalist
  • First Question
  • Total activity 9
  • Last activity
  • Member since
  • Following 0 users
  • Followed by 0 users
  • Votes 1
  • Subscriptions 1

Activity overview

Latest activity by Manuel Fernandez de Dios
  • Manuel Fernandez de Dios commented,

    Hi, The problem is that in this type of model the presolve slows down the solution of the problem. I ran the AMPL version with presolve off, but the R API version with presolve on. That's why I got...

  • Manuel Fernandez de Dios commented,

    Thanks Matthias, R API interacts with Gurobi with files or by memory? Cheers Manuel  

  • Manuel Fernandez de Dios commented,

    Sorry Matthias, It's the same problem, log files extracts are from different iterations. Here is the first iteration in both AMPL   Presolve eliminates 0 constraints and 68 variables.Adjusted probl...

  • Manuel Fernandez de Dios commented,

    Hi Log file extract (1 iteration) R API Gurobi 9.5.1 (linux64, R) logging started Xov 14 Abr 2022 17:49:02Set parameter UsernameSet parameter LogFile to value "TSP.log"Academic license - for non-co...

  • Manuel Fernandez de Dios commented,

    Thanks a lot, Matthias Cheers, Manuel

  • Manuel Fernandez de Dios commented,

    Hi, something like that result <- gurobi(model, params) time=result$runtimewhile(#----subtour found--------){    # re = new subtour elimination constraint    model$A=rbind(model$A,re)    model$sens...

  • Manuel Fernandez de Dios created a post,

    R API slower than AMPL?

    Answered

    I am making a comparison between solving a problem with Gurobi using AMPL and using directly the R API. The result I find is surprising, it is much faster to solve with AMPL (computing only solver ...