org.opentripplanner.api.resource

Class SIsochrone

java.lang.Object

org.opentripplanner.api.common.RoutingResource

org.opentripplanner.api.resource.SIsochrone

@Path(value="/routers/{routerId}/isochroneOld")
public class SIsochrone
extends RoutingResource

This is the original Isochrone class provided by Stefan Steineger. Another implementation has been provided by Laurent Grégoire (isochrone2).

Field Summary

Fields

Modifier and Type	Field and Description
double	angleLimitForUShapeDetection
double	concaveHullAlpha Parameter for concave hull computation, i.e.
double	distanceToleranceForUShapeDetection
boolean	doSpeedTest
double	maxUserSpeed To calculate the length of sub-edges and eventually to detect u-shaped roads, in m/sec (will be set later dependent on mode)
double	offRoadWalkspeed Walkspeed between user indicated position and road 3000 m/h = 0.83333 m/sec
static String	RESULT_TYPE_EDGES
static String	RESULT_TYPE_POINTS
static String	RESULT_TYPE_SHED
long	shedCalcMethodSwitchTimeInSec To decide between edge-based or point-based calculation of sheds, i.e.

Fields inherited from class org.opentripplanner.api.common.RoutingResource

arriveBy, bannedAgencies, bannedRoutes, bannedStops, bannedStopsHard, bannedTrips, batch, bikeBoardCost, bikeSpeed, bikeSwitchCost, bikeSwitchTime, clampInitialWait, date, disableRemainingWeightHeuristic, fromPlace, ignoreRealtimeUpdates, intermediatePlaces, maxPreTransitTime, maxTransfers, maxWalkDistance, minTransferTime, modes, nonpreferredTransferPenalty, numItineraries, optimize, otherThanPreferredRoutesPenalty, otpServer, preferredAgencies, preferredRoutes, reverseOptimizeOnTheFly, routerId, showIntermediateStops, startTransitStopId, startTransitTripId, time, toPlace, transferPenalty, triangleSafetyFactor, triangleSlopeFactor, triangleTimeFactor, unpreferredAgencies, unpreferredRoutes, waitAtBeginningFactor, waitReluctance, walkBoardCost, walkReluctance, walkSpeed, wheelchair

Constructor Summary

Constructors

Constructor and Description
SIsochrone()

Method Summary

Modifier and Type	Method and Description
double	getFirstToLastSegmentAngle(com.vividsolutions.jts.geom.Geometry geometry) Computes the angle from the first point to the last point of a LineString or MultiLineString.
String	getIsochrone(double walkmins, String output) Calculates walksheds for a given location, based on time given to walk and the walk speed.

Methods inherited from class org.opentripplanner.api.common.RoutingResource

buildRequest

Methods inherited from class java.lang.Object

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

Field Detail

RESULT_TYPE_POINTS

public static final String RESULT_TYPE_POINTS

See Also:

Constant Field Values

RESULT_TYPE_SHED

public static final String RESULT_TYPE_SHED

See Also:

Constant Field Values

RESULT_TYPE_EDGES

public static final String RESULT_TYPE_EDGES

See Also:

Constant Field Values

offRoadWalkspeed

public double offRoadWalkspeed

Walkspeed between user indicated position and road 3000 m/h = 0.83333 m/sec

shedCalcMethodSwitchTimeInSec

public long shedCalcMethodSwitchTimeInSec

To decide between edge-based or point-based calculation of sheds, i.e. hulls. Will be set later again.

angleLimitForUShapeDetection

public double angleLimitForUShapeDetection

distanceToleranceForUShapeDetection

public double distanceToleranceForUShapeDetection

maxUserSpeed

public double maxUserSpeed

To calculate the length of sub-edges and eventually to detect u-shaped roads, in m/sec (will be set later dependent on mode)

concaveHullAlpha

public double concaveHullAlpha

Parameter for concave hull computation, i.e. the maximal (triangulation) edge length in degrees

doSpeedTest

public boolean doSpeedTest

Constructor Detail

SIsochrone

public SIsochrone()

Method Detail

getIsochrone

@GET
 @Produces(value="application/json")
public String getIsochrone(@QueryParam(value="walkTime") @DefaultValue(value="15")
                                                                     double walkmins,
                                                                     @QueryParam(value="output") @DefaultValue(value="POINTS")
                                                                     String output)
                                                              throws Exception

Calculates walksheds for a given location, based on time given to walk and the walk speed. Depending on the value for the "output" parameter (i.e. "POINTS", "SHED" or "EDGES"), a different type of GeoJSON geometry is returned. If a SHED is requested, then a ConcaveHull of the EDGES/roads is returned. If that fails, a ConvexHull will be returned.

The ConcaveHull parameter is set to 0.005 degrees. The offroad walkspeed is assumed to be 0.83333 m/sec (= 3km/h) until a road is hit.

Note that the set of EDGES/roads returned as well as POINTS returned may contain duplicates. If POINTS are requested, then not the end-points are returned at which the max time is reached, but instead all the graph nodes/crossings that are within the time limits.

In case there is no road near by within the given time, then a circle for the walktime limit is created and returned for the SHED parameter. Otherwise the edge with the direction towards the closest road. Note that the circle is calculated in Euclidian 2D coordinates, and distortions towards an ellipse will appear if it is transformed/projected to the user location.

An example request may look like this: localhost:8080/otp-rest-servlet/ws/iso?layers=traveltime&styles=mask&batch=true&fromPlace=51.040193121307176 %2C-114.04471635818481&toPlace =51.09098935%2C-113.95179705&time=2012-06-06T08%3A00%3A00&mode=WALK&maxWalkDistance=10000&walkSpeed=1.38&walkTime=10.7&output=EDGES Though the first parameters (i) layer, (ii) styles and (iii) batch could be discarded.

Parameters:

walkmins - Maximum number of minutes to walk.

output - Can be set to "POINTS", "SHED" or "EDGES" to return different types of GeoJSON geometry. SHED returns a ConcaveHull or ConvexHull of the edges/roads. POINTS returns all graph nodes that are within the time limit.

Returns:

a JSON document containing geometries (either points, lineStrings or a polygon).

Throws:

Exception

getFirstToLastSegmentAngle

public double getFirstToLastSegmentAngle(com.vividsolutions.jts.geom.Geometry geometry)

Computes the angle from the first point to the last point of a LineString or MultiLineString. TODO: put this method into org.opentripplanner.common.geometry.DirectionUtils

Parameters:

geometry - a LineString or a MultiLineString

Returns: