Hello, I believe there are a number of issues with the computation: - The sum of speeds overestimates the distance slightly because the vehicle does not travel in the first step (it is inserted with the specified departSpeed after vehicle movements have taken place) - The sum of route lengths was missing the length of the first edge - The sum of route lengths misses short edges that were passed over in a single step. You can easily see that this happens because each normal edge must be followed by an internal edge (prefixed with ':') in the complete trajectory.
regards, Jakob 2017-03-27 18:03 GMT+02:00 Matěj Kubička < [email protected]>: > Hello, > I believe that I have got these covered. I am also careful not to count > twice the same road on lane change. > > A minimum working example in Python 2 is attached. It contains recorded > trip of the vehicle '0FRtoLU.0' in latest LuST plus a few lines of code > that expose the problem I am having. > > Thank you Jakob, > Matej. > > > On 27/03/2017 16:02, Jakob Erdmann wrote: > > Hello, > the simulation uses the lane lengths from the net.xml. Possible sources of > discrepancy: > - forgetting to count the lengths of internal lanes (lanes within > intersections) > - distance traveled in the last stop before leaving the network (i.e. the > vehicle travles 20m/s in the last step but only drives 10m in the network > and then the route ends) > - integration method to compute distance from speed: By default sumo uses > Euler integration. This means the speed in each step is converted directly > into distance. You may activate ballistic integration using the option > --step-method.ballistic which computes distances from the average of the > speed before and after the step. > > If none of the above serve as an explanation I do need a (preferably > short) error example with input files. > regards, > Jakob > > 2017-03-27 14:00 GMT+02:00 Matěj Kubička <matej.kubicka@l2s. > centralesupelec.fr>: > >> Hello, >> >> Is it possible that lane lengths (extracted from the .net.xml file) are >> not the ones that SUMO uses in simulation? If I compute vehicle travel >> distance based on sum of lane-lengths I get quite a different distance >> than when I integrate over the speed profile.. >> >> What causes these differences? Do you need a working example? >> >> Thanks in advance, >> Matej. >> >> >> >> ------------------------------------------------------------ >> ------------------ >> Check out the vibrant tech community on one of the world's most >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot >> _______________________________________________ >> sumo-user mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/sumo-user >> > > > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ sumo-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/sumo-user
