Iason Liagkas

Hello guys, What does a large matrix coefficient cause to our problem? can we say that the results will be very sensitive to coefficient values? what would be the consequences of this situation? Ki...

Hello guys, I have created a function named SP_define and inside I have formed an optimization model named SPmodel = gp.Model('SP'). On the final line of the function, I have written: return SPmode...

Hello guys, I am running the benders algo, When my subproblem is feasible I am using the following line to get the dual variable value:  gp.quicksum(BigM*deltars2kE[r,s,k]*subproblem.getConstrByNam...

Hello Guys, I am trying to code a Python function to build a model inside. The name of the function is SP_define. The function returns the model only. I run the below code. When I print the model I...

Hello guys on a previous post I have found : https://support.gurobi.com/hc/en-us/community/posts/7197240325905-How-to-update-value-of-parameter-during-model-iteration-?input_string=model%20paramete...

Hello guys, in my lp file for the model description I am getting 0 as coefficient for a variable that should have coefficient=1. bellow is the output: Is there anything wrong with this?  \ Model SP...

Hello guys, do you know how does Gurobi handle the multiplication of two continuous variables under the hood?  I was searching how to linearize this calculation and I came across McCormick envelope...

Hello guys, I am running a code and every time I run it I get a different result in terms of time to get the solution and also in terms of optimality gap. The objective function has a different res...

Hello guys, I am modeling a problem relative to traffic equilibrium, and when I add more than a certain number of traffic origin-destination pairs it becomes infeasible. Does this mean that I am re...

Hello guys, I have been running a code that solves a problem but I do not know if the problem is feasible or not, so my questions are 1) if the log file has been running for 24 hours and I have not...