faq 191594515

Multiple network reads depending on population size

by Gregory Macfarlane on 2018-02-28 21:30:25

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I'm trying to generate dummy plans from a trip matrix obtained from a four-step regional travel demand model. The matrix is stored in an OMX file, and represents decimal flows between points in a region.

I've created a playground workspace on our fork of the playgrounds repo (module tf) with a complete setup. But I can illustrate the problem here:

String dir = "tf/src/main/resources/";
 Config config = ConfigUtils.loadConfig(dir + "config.xml");
 Scenario scenario = ScenarioUtils.createScenario(config);
 //sampling rate
 Double samplingRate = 0.1;
 //writes population.xml.gz plans file
 makeOmxTrips(dir, scenario, samplingRate);
 Controler controler = new Controler(config);
 controler.run();
 

Basically, the makeOmxTrips method reads the matrix file and converts the decimal flows into discrete trips that make two "Home" activities, one at the origin point and one at the destination point. The samplingRate parameter determines the rate at which flows are converted into plans, with 0.01 meaning one person-plan for every 100 decimal trips.

But this is all background. In the example above, everything works as expected. But if I change the samplingRate to 1.0, the scenario appears to attempt to load the network file multiple times. This creates an error where IDs are repeated, because of course they are.

2018-02-28 16:02:26,920  INFO PopulationImpl:112  person # 256
 2018-02-28 16:02:26,943  INFO ScenarioLoaderImpl:108 loading scenario from base directory: /Users/gregmacfarlane/playgrounds/
 2018-02-28 16:02:26,944  INFO ScenarioLoaderImpl:130 loading network from file:/Users/gregmacfarlane/playgrounds/tf/src/main/resources/highway_network.xml.gz
 2018-02-28 16:02:26,945  INFO MatsimNetworkReader:95 using network_v2-reader.
 2018-02-28 16:02:26,946  INFO MatsimXmlParser:270 Trying to load http://www.matsim.org/files/dtd/network_v2.dtd. In some cases (e.g. network interface up but no connection), this may take a bit.
 2018-02-28 16:02:26,944  WARN MatsimXmlParser:155 starting to parse xml from url file:/Users/gregmacfarlane/playgrounds/tf/src/main/resources/highway_network.xml.gz ...
 2018-02-28 16:02:27,161  INFO ScenarioLoaderImpl:108 loading scenario from base directory: /Users/gregmacfarlane/playgrounds/
 2018-02-28 16:02:27,161  INFO ScenarioLoaderImpl:130 loading network from file:/Users/gregmacfarlane/playgrounds/tf/src/main/resources/highway_network.xml.gz
 2018-02-28 16:02:27,162  WARN MatsimXmlParser:155 starting to parse xml from url file:/Users/gregmacfarlane/playgrounds/tf/src/main/resources/highway_network.xml.gz ...
 2018-02-28 16:02:27,163  INFO MatsimNetworkReader:95 using network_v2-reader.
 2018-02-28 16:02:27,163  INFO MatsimXmlParser:270 Trying to load http://www.matsim.org/files/dtd/network_v2.dtd. In some cases (e.g. network interface up but no connection), this may take a bit.
 2018-02-28 16:02:27,368  WARN MatsimXmlParser:155 starting to parse xml from url 
 ...
 ...
 ...
 2) Error in custom provider, java.lang.IllegalArgumentException: There exists already a node with id = 0.
 Existing node: [id=0][coord=[x=299666.0758658158][y=163294.94229271446]] [type=null][nof_inlinks=1][nof_outlinks=1]
 Node to be added: [id=0][coord=[x=299666.0758658158][y=163294.94229271446]] [type=null][nof_inlinks=0][nof_outlinks=0].
 Node is not added to the network.
   at org.matsim.core.scenario.ScenarioByConfigModule.createScenario(ScenarioByConfigModule.java:9) (via modules: com.google.inject.util.Modules$CombinedModule -> com.google.inject.util.Modules$CombinedModule -> org.matsim.core.controler.AbstractModule$4 -> com.google.inject.util.Modules$OverrideModule -> org.matsim.core.scenario.ScenarioByConfigModule)
   at org.matsim.core.scenario.ScenarioByConfigModule.createScenario(ScenarioByConfigModule.java:9) (via modules: com.google.inject.util.Modules$CombinedModule -> com.google.inject.util.Modules$CombinedModule -> org.matsim.core.controler.AbstractModule$4 -> com.google.inject.util.Modules$OverrideModule -> org.matsim.core.scenario.ScenarioByConfigModule)
   while locating org.matsim.api.core.v01.Scenario

Complete logfile attached.

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Comments: 1

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Re: Multiple network reads depending on population size

by Kai Nagel on 2018-02-28 21:39:50

Can't say, not enough information, sorry. What I can say is that the code snippet that you provide seems inconsistent: you are creating a scenario, then using it in makeOmxTrip, and then somehow not using it any further. But maybe that is a typo? In general I would recommend the following sequence:

Config config = ConfigUtils.loadConfig(configFileName);
 Scenario scenario = ScenarioUtils.loadScenario( config ) ; // note _load_, not create
 // modify scenario, e.g. add trips from omx
 Controler controler = new Controler( scenario ) ; // note scenario as argument

PS: In general we would recommend to clone matsim-example-project as a starting point for own programming, and matsim-code-examples for code examples. playgrounds contain lots of code that should not be used any more.