Package edu.gsu.cs.dmlab.solgrind.algo

Class SequenceUtils

java.lang.Object

edu.gsu.cs.dmlab.solgrind.algo.SequenceUtils

public class SequenceUtils
extends Object

Author:

Data Mining Lab, Georgia State University

Constructor Summary

Constructors

Constructor	Description
SequenceUtils()

Method Summary

Modifier and Type	Method	Description
static Trajectory	createTailWindow(Instance ins, float tailRatio, double bufferDistance, long tailValidity, long samplingInterval)	Generates tail window from an instance
static Trajectory	createTailWindow(Instance ins, long tailInterval, double bufferDistance, long tailValidity, long samplingInterval)	Generates tail window from an instance
static TwoSequence	discoverFollowRelationship(InstanceData headData, Trajectory head, InstanceData tailData, Trajectory tailW, String ciType)	Given two instance trajectories in form of InstanceData objects and trajectories (head and tailWindow), method returns an TwoSequence (2-sequence) object, which describes a follow relationship
static Instance	generateHead(Instance ins, long headInterval)	Generates head segment using head interval strategy Gets the trajectory segment that covers initial 'headInterval' time interval.
static Instance	generateHeadwithRatio(Instance ins, double headRatio)	Generates head segment using head ratio strategy Gets the trajectory segment that covers initial 'headRatio' amount of trajectory's lifespan.
static Trajectory	generateTail(Instance ins, float tailRatio)	Generates tail segment using tail ratio strategy Gets the trajectory segment that covers last 'tailRatio' amount of trajectory's lifespan.
static Trajectory	generateTail(Instance ins, long tailInterval)	Generates the tail segment using tail interval strategy Gets the trajectory segment that covers last 'tailInterval' time interval.
static Trajectory	generateTailBuffer(Trajectory tail, double bufferDistance)	Generates tail buffer from a given tail segment of the trajectory using bufferDistance parameter.
static Instance	generateTailWindow(Instance instance, long tailInterval, double bufferDistance, long tailValidityCount)
static Trajectory	generateTailWindow(Trajectory tailBuffer, long tailValidity, long samplingInterval)	Generates tail window using the buffered tail trajectory by propagating it
static Instance	generateTailWindowWithRatio(Instance instance, double tailRatio, double bufferDistance, long tailValidityCount)
static Set<InstanceSequence>	instanceSequenceConnector(HashSet<InstanceSequence> instanceSequences, int desiredLength)	Gets a set of instance sequences (InstanceSequence objects), and connects them based on the equality of prefix and suffix (of possible followee and follower instance sequences)
static Trajectory	sampleTGPairs(Trajectory traj, long samplingInterval)	Based on a sampling interval, sample the time-geometry pairs in the trajectory

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceUtils

public SequenceUtils()

Method Detail

generateHead

public static Instance generateHead(Instance ins,
                                    long headInterval)

Generates head segment using head interval strategy Gets the trajectory segment that covers initial 'headInterval' time interval.

Parameters:

ins - - instance whose head is to be generated

headInterval - - head interval parameter

Returns:

head segment of the instance which is a Trajectory object

generateHeadwithRatio

public static Instance generateHeadwithRatio(Instance ins,
                                             double headRatio)

Generates head segment using head ratio strategy Gets the trajectory segment that covers initial 'headRatio' amount of trajectory's lifespan.

Parameters:

ins -

headRatio -

Returns:

generateTail

public static Trajectory generateTail(Instance ins,
                                      long tailInterval)

Generates the tail segment using tail interval strategy Gets the trajectory segment that covers last 'tailInterval' time interval.

Parameters:

ins - - instance whose head is to be generated

tailInterval - - tail interval parameter

Returns:

tail segment of the trajectory

generateTail

public static Trajectory generateTail(Instance ins,
                                      float tailRatio)

Generates tail segment using tail ratio strategy Gets the trajectory segment that covers last 'tailRatio' amount of trajectory's lifespan.

Parameters:

ins -

tailRatio -

Returns:

generateTailBuffer

public static Trajectory generateTailBuffer(Trajectory tail,
                                            double bufferDistance)

Generates tail buffer from a given tail segment of the trajectory using bufferDistance parameter. Simply applies a spatial buffer to all geometries

Parameters:

tail - - tail trajectory segment

bufferDistance - - buffer distance parameter

Returns:

generateTailWindow

public static Trajectory generateTailWindow(Trajectory tailBuffer,
                                            long tailValidity,
                                            long samplingInterval)

Generates tail window using the buffered tail trajectory by propagating it

Parameters:

tailBuffer - - buffered tail trajectory

tailValidity - - the period that will be used to propagate the tgpairs in trajectory

samplingInterval - - the sampling interval for creating a better tail window

Returns:

- tail window trajectory

sampleTGPairs

public static Trajectory sampleTGPairs(Trajectory traj,
                                       long samplingInterval)

Based on a sampling interval, sample the time-geometry pairs in the trajectory

Parameters:

traj -

samplingInterval -

Returns:

generateTailWindowWithRatio

public static Instance generateTailWindowWithRatio(Instance instance,
                                                   double tailRatio,
                                                   double bufferDistance,
                                                   long tailValidityCount)

generateTailWindow

public static Instance generateTailWindow(Instance instance,
                                          long tailInterval,
                                          double bufferDistance,
                                          long tailValidityCount)
                                   throws org.locationtech.jts.io.ParseException

Throws:

org.locationtech.jts.io.ParseException

createTailWindow

public static Trajectory createTailWindow(Instance ins,
                                          long tailInterval,
                                          double bufferDistance,
                                          long tailValidity,
                                          long samplingInterval)

Generates tail window from an instance

Parameters:

ins -

tailInterval -

bufferDistance -

tailValidity -

samplingInterval -

Returns:

createTailWindow

public static Trajectory createTailWindow(Instance ins,
                                          float tailRatio,
                                          double bufferDistance,
                                          long tailValidity,
                                          long samplingInterval)

Generates tail window from an instance

Parameters:

ins -

tailRatio -

bufferDistance -

tailValidity -

samplingInterval -

Returns:

discoverFollowRelationship

public static TwoSequence discoverFollowRelationship(InstanceData headData,
                                                     Trajectory head,
                                                     InstanceData tailData,
                                                     Trajectory tailW,
                                                     String ciType)

Given two instance trajectories in form of InstanceData objects and trajectories (head and tailWindow), method returns an TwoSequence (2-sequence) object, which describes a follow relationship

Parameters:

headData - - the data for head

head - - head segment

tailData - - the data for tail window

tailW - - tail window segment

ciType - - chain index type

Returns:

instanceSequenceConnector

public static Set<InstanceSequence> instanceSequenceConnector(HashSet<InstanceSequence> instanceSequences,
                                                              int desiredLength)

Gets a set of instance sequences (InstanceSequence objects), and connects them based on the equality of prefix and suffix (of possible followee and follower instance sequences)

Parameters:

instanceSequences - - set of instance sequences to be examined

desiredLength - - the length of resulting instance sequences

Returns: