org.opentripplanner.profile

Class RaptorWorker

java.lang.Object

org.opentripplanner.profile.RaptorWorker

public class RaptorWorker
extends Object

A RaptorWorker carries out RAPTOR searches on a pre-filtered, compacted representation of all the trips running during a given time window. It originated as a rewrite of our RAPTOR code that would use "thin workers", allowing computation by a generic function-execution service like AWS Lambda. The gains in efficiency were significant enough that RaptorWorkers are now used in the context of a full-size OTP server executing spatial analysis tasks. We can imagine that someday all OTP searches, including simple point-to-point searches, may be carried out on such compacted tables, including both the transit and street searches (via a compacted street network in a column store or struct-like byte array using something like the FastSerialization library). This implements the RAPTOR algorithm; see http://research.microsoft.com/pubs/156567/raptor_alenex.pdf

Field Summary

Fields

Modifier and Type	Field and Description
static int	MONTE_CARLO_COUNT_PER_MINUTE The number of randomized frequency schedule draws to take for each minute of the search.
static int	TOTAL_MONTE_CARLO_COUNT If there are no schedules, the number of Monte Carlo draws to take
static int	UNREACHED

Constructor Summary

Constructors

Constructor and Description
RaptorWorker(RaptorWorkerData data, ProfileRequest req)

Method Summary

Modifier and Type	Method and Description
void	advance()
boolean	doOneRound(int[] bestTimes, int[] bestNonTransferTimes, int[] previousPatterns, boolean useFrequencies)
void	doPropagation(int[] timesAtTransitStops, int[] timesAtTargets, int departureTime) Propagate from the transit network to the street network.
void	dumpVariableByte(int[][] array)
PropagatedTimesStore	runRaptor(Graph graph, gnu.trove.map.TIntIntMap accessTimes, int[] nonTransitTimes, TaskStatistics ts)
void	runRaptorFrequency(int departureTime, int[] bestTimes, int[] bestNonTransferTimes, int[] previousPatterns) Run a RAPTOR search using frequencies
void	runRaptorScheduled(gnu.trove.map.TIntIntMap initialStops, int departureTime) Run a raptor search not using frequencies

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

UNREACHED

public static final int UNREACHED

See Also:

Constant Field Values

MONTE_CARLO_COUNT_PER_MINUTE

public static final int MONTE_CARLO_COUNT_PER_MINUTE

The number of randomized frequency schedule draws to take for each minute of the search. We loop over all departure minutes and do a schedule search, and then run this many Monte Carlo searches with randomized frequency schedules within each minute. It does not need to be particularly high as it happens each minute, and there is likely a lot of repetition in the scheduled service (i.e. many minutes look like each other), so several minutes' monte carlo draws are effectively pooled.

See Also:

Constant Field Values

TOTAL_MONTE_CARLO_COUNT

public static final int TOTAL_MONTE_CARLO_COUNT

If there are no schedules, the number of Monte Carlo draws to take

See Also:

Constant Field Values

Constructor Detail

RaptorWorker

public RaptorWorker(RaptorWorkerData data,
                    ProfileRequest req)

Method Detail

advance

public void advance()

runRaptor

public PropagatedTimesStore runRaptor(Graph graph,
                                      gnu.trove.map.TIntIntMap accessTimes,
                                      int[] nonTransitTimes,
                                      TaskStatistics ts)

Parameters:

accessTimes - a map from transit stops to the time it takes to reach those stops

nonTransitTimes - the time to reach all targets without transit. Targets can be vertices or points/samples.

dumpVariableByte

public void dumpVariableByte(int[][] array)

runRaptorScheduled

public void runRaptorScheduled(gnu.trove.map.TIntIntMap initialStops,
                               int departureTime)

Run a raptor search not using frequencies

runRaptorFrequency

public void runRaptorFrequency(int departureTime,
                               int[] bestTimes,
                               int[] bestNonTransferTimes,
                               int[] previousPatterns)

Run a RAPTOR search using frequencies

doOneRound

public boolean doOneRound(int[] bestTimes,
                          int[] bestNonTransferTimes,
                          int[] previousPatterns,
                          boolean useFrequencies)

doPropagation

public void doPropagation(int[] timesAtTransitStops,
                          int[] timesAtTargets,
                          int departureTime)

Propagate from the transit network to the street network. Uses allStopsTouched to determine from whence to propagate. This is valid both for randomized frequencies and for schedules, because the stops that have been updated will be in allStopsTouched.