fact.features.watershed

Class ClusterArrivalTimes

java.lang.Object

fact.features.watershed.ClusterArrivalTimes

All Implemented Interfaces:

stream.Processor

public class ClusterArrivalTimes
extends Object
implements stream.Processor

This class clusters shower pixels(!) by their arrival times. In this case a region growing algorithm is used, which works like 1. Find seed (= an unflagged shower pixel). For the first iteration the first shower pixel is used as seed (shower[0]). This is kind of a random seed and could cause different cluster results for the same event for different runs! 2. Find all neighbor pixel which have the smallest difference in arrival time. This pixel is the 'current' pixel.

3. Find all flagged neighbor pixel for the 'current' pixel. 4. Search for the flagged pixel which has the smallest difference in arrival time. 5. Check if the smallest difference is under a threshold (hardcode at the moment, could be variable, maybe std of all arrival times in cluster so far?) 6. difference < threshold: current pixel gets the same cluster id as the neighbor pixel with this difference difference > threshold: current pixel gets a new cluster ID 7. Search for the next current or seed pixel to cluster. Keep in mind that only shower pixels should be clustered. --> iterate step 3. - 7. until all shower pixels have a cluster ID

Created by lena on 09.02.16.

Field Summary

Fields

Modifier and Type	Field and Description
String	arrivaltimePosKey
String	photonchargeKey
String	showerKey
double	threshold

Constructor Summary

Constructors

Constructor and Description
ClusterArrivalTimes()

Method Summary

Modifier and Type	Method and Description
stream.Data	process(stream.Data data)

Methods inherited from class java.lang.Object

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

Field Detail

threshold

@Parameter(required=false,
           description="Threshold to decide whether a pixel belongs to a cluster or not",
           defaultValue="3")
public double threshold

showerKey

@Parameter(required=true,
           description="Input key for pixel set (aka shower pixel)")
public String showerKey

arrivaltimePosKey

@Parameter(required=false,
           description="Input key for arrivaltime positions",
           defaultValue="arrivalTimePos")
public String arrivaltimePosKey

photonchargeKey

@Parameter(required=false,
           description="Input key for calculated photon charge",
           defaultValue="photoncharge")
public String photonchargeKey

Constructor Detail

ClusterArrivalTimes

public ClusterArrivalTimes()

Method Detail

process

public stream.Data process(stream.Data data)

Specified by:

process in interface stream.Processor