Thanks, the discrepancy has gone. ~Matej. On 27/03/2017 21:39, Jakob Erdmann wrote: > 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] > <mailto:[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 >> <[email protected] >> <mailto:[email protected]>>: >> >> 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] >> <mailto:[email protected]> >> https://lists.sourceforge.net/lists/listinfo/sumo-user >> <https://lists.sourceforge.net/lists/listinfo/sumo-user> >> >> > >
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