Hello community,
I’m looking for a strategy to determine the optimal max iterations value “vra.setMaxIterations(maxIterations)” : trade-off between best final results and lowest time to process jsprit.
I guess it depends on the used algorithm and the number of visited node, am i correct?
For instance, it is not necessary to use a high max iterations for simple problem.
Thank you,
Martin
No answer, nevermind, max iterations is an algo parameter…
By the way, on jpsrit 1.6.2, to build a problem :
final VehicleRoutingProblem vrp = vrpBuilder.build();
final VehicleRoutingAlgorithmBuilder vraBuilder = new VehicleRoutingAlgorithmBuilder(vrp, xml_file);
On jsprit 1.7.0, VehicleRoutingAlgorithmBuilder doesn’t exist anymore, did you remove xml configuration way? Now the appropriate way is to configure algo by coding?
Yes, configure it in code like this: jsprit/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/box/SchrimpfFactory.java at master · graphhopper/jsprit · GitHub
Unfortunately, you need to find out yourself. Just conduct a sensitivity study based on your problems with varying max iterations. For very simple problems, you dont need many iterations. However, you can also use a number of termination strategies you can find here: jsprit/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/termination at master · graphhopper/jsprit · GitHub. For example, VariationCoefficientTermination terminates the algo if variations of costs of found solutions are less than a threshold variation.
BTW: you can still use the xml config by using the jsprit-io module. It is just removed from the core.