Sonja Mars

Hi, These are modules that don't come with every Python distribution, you have to install them separately or use a different Python distribution. If you are using Anaconda Python you can easily ins...

Hi, Can you share complete log files for these runs? Without them it is tricky to say, why it needed 50 seconds and now needs 2 hours. Also please note, there is no way of predicting the run time o...

Hi, Have you looked at our examples? They show how objectives and other linear expressions can be coded up. Best regards,   Sonja

Hi, I am sorry, we don't offer a attribute or an API method to query the reading time or the presolve time. The only way of getting these number is to parse the log file. Best regards,   Sonja

Hi, Is this a continuous SDP or a Mixed-Integer SDP that you are looking at? Please note, lazy constraints are used to cutoff infeasible integer solutions of a MIP. You cannot use them to do some o...

Hi, I am sorry, I cannot see the additional logging. Can you please explain what I should see in the log? A few comments: What does you MIPSOL calback look like? Please make sure to always add all...

Hi Larry, Are you generating these instances all at the same time (in parallel) or one after another? If the first is the case you need a machine with lots of RAM. Disk space is not really interes...

Hi, Please note Gurobi environments GRBEnv are not thread safe. So if you do something like this, you will have to make sure that every model has its own GRBEnv. This is a bit tricky in Python, ple...

Hi, For getting any objective values and/or solution vectors during an optimization, you can use a MIPSOL Callback. Within this you can query MIPSOL_SOL and write it down to a file. Best regards,  ...

Hi, Sorry, I don't understand what you are looking for. What exactly do you want to do? Do you want to use Gurobi solve a VRP or do you want to write a Branch-and-Cut algorithm yourself? Best regar...