Description

Instances for the recoverable selection problem under discrete uncertainty set could be found on this page. Here, we use n, p, N and k when referring to the number of items, number of items one wants to choose, number of scenarios and recovery parameter, respectively.

This page will be updated regularly

Instance Format

The first four numbers used to label each instance file represent n, p, N and k in the exact same order. In addition, the last number shows the instance number with the given size. For each considered size 50 instances are generated. The instance files contain N+2 lines. The first line demonstrates n, p, N, k. The second line is a n-vector representing cost of each item in the first stage and the remaining lines illustrate N different scenarios including n item costs in the second stage.

Output

Software Tool

On the following link, the generator codes for the given set of instances can be found. Each folder contains three files named main, selection and sel. The main file introduces the input parameters. The selection file consists of all the function we used and the sel file has all the classes and their parameters defined. The input parameters, which should be given through the command line are different for each problem.

In this setting the parameters must be given the the exact following order for the selection problem:

n: number of items

p: number of items to be selected

N: number of scenarios

delta: the maximum number of items which can be changed in the second stage

param: method of instance generation (param=0 for sampling, param=1 for HIRO with only changing the first stage scenario and param=2 for HIRO with changing both the first and second stage scenarios)

R: methods of sampling or starting the HIRO (R=0 for RR_D_U) (R=1 for RR_D_1) (R=2 for RR_D_2)

timelimit: the time limit for finishing the process, in particular for the HIRO

budget: maximum permitted adjustment for each member of a scenario random

seed: this allows the user to generate different instances when all other parameters are the same

Reference

The information on this page has been created based on the paper “Benchmarking Problems for Robust Discrete Optimization” by Dr. Marc Goerigk (Network and Data Science Management, University of Siegen, Germany) and Mohammad Khosravi (Network and Data Science Management, University of Siegen, Germany).