Modeling code

Releases of OPTANO Modeling 2.15.0 und 2.16.0

New features und developments in the API

OPTANO Modeling is the smart module of your software. It is the .net API which enables mathematical programming in your software. The latest version of OPTANO Modeling is available as a NuGet Package and can be downloaded free of charge: www.nuget.org/packages/optano.modeling

Release OPTANO Modeling 2.15

Apart from the constant improvement to performance, the release of OPTANO Modeling 2.15 is all about multi-criteria optimization.

The degradation of objective values

In the emulated mode of OPTANO Modeling for multi-hierarchical optimization, it is now possible to define the maximum permissible degradation of the objective value for later levels of the optimization.

This enables you to answer questions such as “What does the cost-optimized transport plan in a flow maximization problem look like?”, followed by:  “To what extent can we improve the satisfaction of demands with a cost increase of up to x%?”

This feature is supported by all solvers.

Hierarchy level specific MIP gaps and time limits
 

So far it has only been possible to define one MIP gap for all optimization levels as well as specifying one global time limit.  If the time limit had already been reached during the first optimization level, later levels  were never considered by the solver.
OPTANO Modeling 2.15 now allows you to set time limits for individual levels: “Optimization in total – 5 hrs: Level 1 no longer than 2 hours, level 2 no longer than 1 hour…”

In combination with the individual MIP gaps, the solution process can be controlled much better, particularly in the case of models where some levels are very complex to solve whereas others are very “easy”.

This feature is now supported by CPLEX 12.8 as well as Gurobi 8.1 in the emulated mode for the multi-hierarchichal optimization of OPTANO Modeling.

Release OPTANO Modeling 2.16

MIPCL Solver

The MIPCL Solver is now supported in Version 2.1.3.

CplexSolver 12.8

In the CplexSolver 12.8, variables and constraints are transmitted per Batch-Query to the native API. In this way, the time required to build the model, especially (very) large models, has been reduced considerably. An extension of the CplexSolver log output also improves the overview of the solution process.

Gurobi Configuration

In the Gurobi Configuration, three options concerning access to a size-limited license, which Gurobi has provided for OPTANO Modeling, have been specified:

a) always
b) as a fallback
c) never

This enables you to solve small optimization models during unit testing, without blocking your license for other (“real”) optimization jobs.

An overview of the latest improvements can be found in the Changelog:http://docs.optano.net/modeling/current/changelog.html

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