fact.TriggerEmulation

Class Discriminator

java.lang.Object

fact.TriggerEmulation.Discriminator

public class Discriminator
extends Object

Class that implements a software addaption of a discriminator in the sense of the device used on FACTs FTU (Trigger Unit) boards. (Source: Design and operation of FACT - the first G-APD Cherenkov telescope, DOI: 10.1088/1748-0221/8/06/P06008, P.20) The class contains functions to digitize the signals of a given patch (or a bunch of them) by comparing them to a given threshold. Furhtermore it contains helper functions for the discrimination e.g. conversion between DAC and mV

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Discriminator.DiscriminatorOutput A simple class to hold the result of the discriminator

Field Summary

Fields

Modifier and Type	Field and Description
static int	default_slice

Constructor Summary

Constructors

Constructor and Description
Discriminator()

Method Summary

Modifier and Type	Method and Description
static int	booleanToInt(boolean value)
static double	dacToMillivolt(int amplitude) Convert threshold in DAC units to millivolt units
static Discriminator.DiscriminatorOutput	discriminatePatch(double[] data, int thresholdInDAC, int minTimeOverThresholdInSlices, int skipFirst, int skipLast) Compute the first occurence of a signal that is above a given thresholdInDAC and stays above it for a requested time (minTimeOverThresholdInSlices).
static Discriminator.DiscriminatorOutput[]	discriminatePatches(double[][] data, int thresholdInDAC, int minTimeOverThreshold, int skipFirst, int skipLast) loop over pixels patch by patch and discriminate each patch
static boolean[]	discriminatorOutputsToTriggerPrimitiveArray(Discriminator.DiscriminatorOutput[] discriminatorOutputs) Get the triggerPrimitive members from an array of DiscriminatorOutputs and return them as native boolean array
static int[]	discriminatorOutputsToTriggerSliceArray(Discriminator.DiscriminatorOutput[] discriminatorOutputs) Get the triggerSlice members from an array of DiscriminatorOutputs and return them as native int array
static int	millivoltToDAC(double amplitude) Convert amplitude in DAC units to millivolt units

Methods inherited from class java.lang.Object

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

Field Detail

default_slice

public static int default_slice

Constructor Detail

Discriminator

public Discriminator()

Method Detail

discriminatePatch

public static Discriminator.DiscriminatorOutput discriminatePatch(double[] data,
                                                                  int thresholdInDAC,
                                                                  int minTimeOverThresholdInSlices,
                                                                  int skipFirst,
                                                                  int skipLast)

Compute the first occurence of a signal that is above a given thresholdInDAC and stays above it for a requested time (minTimeOverThresholdInSlices).

Parameters:

data - timeseries

thresholdInDAC - thresholdInDAC of the discriminator in DAC

minTimeOverThresholdInSlices - minimum time (in unit slices) the signal has to stay above the threhold

skipFirst - number of slices to ignore at the beginning of the time series

skipLast - number of slices to ignore at the end of the time series

Returns:

a DiscriminatorOutputObject

discriminatePatches

public static Discriminator.DiscriminatorOutput[] discriminatePatches(double[][] data,
                                                                      int thresholdInDAC,
                                                                      int minTimeOverThreshold,
                                                                      int skipFirst,
                                                                      int skipLast)

loop over pixels patch by patch and discriminate each patch

Parameters:

data - array with dimensions [n_patches][number_of_slices]

thresholdInDAC - thresholdInDAC of the discriminator in DAC

minTimeOverThreshold - minimum time the signal has to stay above the threhold

skipFirst - number of slices to ignore at the beginning of the time series

skipLast - number of slices to ignore at the end of the time series

Returns:

array of DiscriminatorOutputObjects

dacToMillivolt

public static double dacToMillivolt(int amplitude)

Convert threshold in DAC units to millivolt units

Parameters:

amplitude - in DAC units

Returns:

amplitude in Millivolts

millivoltToDAC

public static int millivoltToDAC(double amplitude)

Convert amplitude in DAC units to millivolt units

Parameters:

amplitude - in millivolt units

Returns:

amplitude in DAC units

booleanToInt

public static int booleanToInt(boolean value)

discriminatorOutputsToTriggerSliceArray

public static int[] discriminatorOutputsToTriggerSliceArray(Discriminator.DiscriminatorOutput[] discriminatorOutputs)

Get the triggerSlice members from an array of DiscriminatorOutputs and return them as native int array

Parameters:

discriminatorOutputs - array of DiscriminatorOutputs

Returns:

boolean array with trigger slices from DiscriminatorOutput objects

discriminatorOutputsToTriggerPrimitiveArray

public static boolean[] discriminatorOutputsToTriggerPrimitiveArray(Discriminator.DiscriminatorOutput[] discriminatorOutputs)

Get the triggerPrimitive members from an array of DiscriminatorOutputs and return them as native boolean array

Parameters:

discriminatorOutputs - array of DiscriminatorOutputs

Returns:

boolean array with trigger primitives from DiscriminatorOutput objects