Dear Pieter, A student of mine is investigating these problems and has a good grasp of what is going on and what should be improved. Maybe we could talk on Skype in the coming days to save on duplicated efforts...
Best, Matthew On 8 Mar 2014 16:50, Pieter Loof <[email protected]> wrote: Hello, I ran some simple tests to see how well DFRouter is able to generate flows similar to the real data. So far, I noticed that the flow at source detectors is exactly correct, so the vehicles are generated based on the source detectors. But when it comes to the distribution of the vehicles over available routes, DFRouter can make large errors. Attached is a picture that I made, which summarizes the output of a test scenario. The green detector is a source, the red detectors are sinks. The numbers shown at each detector are the number of vehicles that pass in a 3 hour time period, the top number being the real data measurement and the bottom number being the number of vehicles in the simulation. As you can see, this is a simple problem where one vehicle flow should be distributed such that about the right number of vehicles reaches each sink. As you can see from the picture, about 1000 vehicles receive the wrong route. I looked into the code to see how DFRouter computes the vehicle distribution, but I don't really understand what is happening (I looked at the code of RODFNet::buildEdgeFlowMap). So my questions are: 1) Can someone explain to me how DFRouter computes the number of vehicles per route? 2) How large can the errors become, are there any garantuees under certain conditions? 3) Will the computation of vehicles per route be improvement in the (near) future? Best regards, Pieter ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech _______________________________________________ sumo-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/sumo-user
