ParticleD

java.lang.Object
- hephysics.jet.ParticleD

All Implemented Interfaces:

Serializable, Comparable<ParticleD>
```
public class ParticleD
extends Object
implements Comparable<ParticleD>, Serializable
```
A class representing a jet or particle with pre-computed px,py,pz,e (double precision). It uses double types to keep information on 4-meomenta. The merging is done in the 4-momentum space. The class has a minimum dynamic computation to minimize CPU usage.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description
`ParticleD()` Initialize pseudoparticle.
`ParticleD(double px, double py, double pz, double energy)` Initialize from 4-momenta.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(ParticleD a)` Add to this particle another particle.
`void`	`add(ParticleD a, int index)` Add to this particle another particle.
`void`	`addConstituent(int i)`
`void`	`cachePhiRapidity()` The method precomputers Phi, Rapidity and Pt2 and store them.
`int`	`compareTo(ParticleD o)` Comparator.
`ParticleD`	`copy(ParticleD o)` Copy a particle.
`double`	`e()` Get energy.
`double`	`et()` Compute transverse energy.
`double`	`et2()` Compute transverse energy squared.
`double`	`eta()` Compute pseudorapidity.
`int[]`	`getConstituents()` Get indexes of constituents, iff filled with the "add" method
`List<Integer>`	`getConstituentsList()` Get indexes of constituents, iff filled with the "add" method
`double`	`getPhi()` Get cached phi
`double`	`getPt()` Get cached Pt.
`double`	`getPt2()` Get cached perp**2.
`double`	`getRapidity()` Get cached rapidity
`int`	`hashCode()` Get a hash code
`double`	`m()` Compute mass.
`double`	`mag()` Compute magnitude sqrt(px2+py2+pz**2)
`double`	`mass()` Compute mass.
`double`	`perp()` Compute transverse momentum (pT).
`double`	`perp2()` Compute pT**2.
`double`	`phi()` Compute Phi
`double`	`px()` Get px.
`double`	`py()` Get py.
`double`	`pz()` Get pz.
`double`	`rapidity()` Compute rapidity.
`void`	`setConstituents(ArrayList<Integer> consts)`
`void`	`setEnergy(double energy)` Set energy.
`void`	`setPhi(double phi)`
`void`	`setPt2(double pt2)`
`void`	`setPtEtaPhiM(double pt, double eta, double phi, double m)` Set 4-momentum of a particle using transverse momentum (pt), pseudorapidity (eta) and azimuthal angle (phi) and mass (m).
`void`	`setPx(double px)`
`void`	`setPxPyPzE(double px, double py, double pz, double energy)` Initialize from 4-momenta.
`void`	`setPy(double py)`
`void`	`setPz(double pz)`
`void`	`setRapidity(double rapidity)`
`String`	`toString()` Convert a particle to a string.

Methods inherited from class java.lang.Object
equals, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - ParticleD
```
public ParticleD()
```
    Initialize pseudoparticle.
  - ParticleD
```
public ParticleD(double px,
                 double py,
                 double pz,
                 double energy)
```
    Initialize from 4-momenta.
    
    Parameters:
    
    px -
    
    py -
    
    pz -
    
    energy -
- Method Detail
  - setPxPyPzE
```
public void setPxPyPzE(double px,
                       double py,
                       double pz,
                       double energy)
```
    Initialize from 4-momenta.
    
    Parameters:
    
    px -
    
    py -
    
    pz -
    
    energy -
  - setPtEtaPhiM
```
public void setPtEtaPhiM(double pt,
                         double eta,
                         double phi,
                         double m)
```
    Set 4-momentum of a particle using transverse momentum (pt), pseudorapidity (eta) and azimuthal angle (phi) and mass (m). In this case, the energy is FastMath.sqrt(px*px+py*py+pz*pz-m*m).
    
    Parameters:
    
    pt - transverse momentum of a particle.
    
    eta - eta (pseudorapidity) .
    
    phi - azimuthal angle
    
    m - mass
  - eta
```
public double eta()
```
    Compute pseudorapidity.
    
    Returns:
    
    pseudorapidity.
  - et2
```
public double et2()
```
    Compute transverse energy squared.
    
    Returns:
    
    transverse energy squared.
  - et
```
public double et()
```
    Compute transverse energy.
    
    Returns:
    
    transverse energy.
  - mass
```
public double mass()
```
    Compute mass.
    
    Returns:
    
    mass
  - m
```
public double m()
```
    Compute mass.
    
    Returns:
    
    mass
  - rapidity
```
public double rapidity()
```
    Compute rapidity. 0.5*log( (m+z)/(m-z) );
    
    Returns:
    
    rapidity
  - mag
```
public double mag()
```
    Compute magnitude sqrt(px**2+py**2+pz**2)
    
    Returns:
    
    mag
  - perp2
```
public double perp2()
```
    Compute pT**2.
    
    Returns:
    
    pt**2
  - perp
```
public double perp()
```
    Compute transverse momentum (pT).
    
    Returns:
    
    Transverse momentum (pt)
  - setEnergy
```
public void setEnergy(double energy)
```
    Set energy.
  - compareTo
```
public int compareTo(ParticleD o)
```
    Comparator. Use pT2 for comparison (in increasing order)
    
    Specified by:
    
    compareTo in interface Comparable<ParticleD>
    
    Parameters:
    
    o - particle
    
    Returns:
  - copy
```
public ParticleD copy(ParticleD o)
```
    Copy a particle.
    
    Parameters:
    
    o -
    
    Returns:
    
    a copy of particle
  - toString
```
public String toString()
```
    Convert a particle to a string.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    a string with the particle
  - px
```
public double px()
```
    Get px.
    
    Returns:
    
    px component
  - py
```
public double py()
```
    Get py.
    
    Returns:
    
    py component
  - pz
```
public double pz()
```
    Get pz.
    
    Returns:
    
    pz component
  - getRapidity
```
public double getRapidity()
```
    Get cached rapidity
    
    Returns:
    
    rapidity
  - getPt2
```
public double getPt2()
```
    Get cached perp**2.
    
    Returns:
    
    perp2.
  - getPt
```
public double getPt()
```
    Get cached Pt.
    
    Returns:
    
    et transverse energy
  - getPhi
```
public double getPhi()
```
    Get cached phi
    
    Returns:
    
    cached phi
  - getConstituentsList
```
public List<Integer> getConstituentsList()
```
    Get indexes of constituents, iff filled with the "add" method
    
    Returns:
    
    list of constituents.
  - setConstituents
```
public void setConstituents(ArrayList<Integer> consts)
```
  - addConstituent
```
public void addConstituent(int i)
```
  - getConstituents
```
public int[] getConstituents()
```
    Get indexes of constituents, iff filled with the "add" method
    
    Returns:
    
    array of constituents.
  - phi
```
public double phi()
```
    Compute Phi
    
    Returns:
  - e
```
public double e()
```
    Get energy.
    
    Returns:
    
    energy component
  - setPx
```
public void setPx(double px)
```
  - setPy
```
public void setPy(double py)
```
  - setPz
```
public void setPz(double pz)
```
  - setRapidity
```
public void setRapidity(double rapidity)
```
  - setPhi
```
public void setPhi(double phi)
```
  - setPt2
```
public void setPt2(double pt2)
```
  - cachePhiRapidity
```
public void cachePhiRapidity()
```
    The method precomputers Phi, Rapidity and Pt2 and store them. Such caching makes faster computations. Use getRapidity(), getPhi(), getPt2() methods to return such values.
  - add
```
public void add(ParticleD a)
```
    Add to this particle another particle. The method also precomputes rapidity, phi and pt2 for fast retrival using getPhi, getRapidity methods.
    
    Parameters:
    
    a -
  - add
```
public void add(ParticleD a,
                int index)
```
    Add to this particle another particle. Also add index of the added particle, which will be stored as an array. The method also precomputes rapidity, phi and et2 for fast retrival using getPhi, getRapidity methods.
    
    Parameters:
    
    a -
    
    index - index of the particle to be stored
  - hashCode
```
public int hashCode()
```
    Get a hash code
    
    Overrides:
    
    hashCode in class Object

Class ParticleD

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ParticleD

ParticleD

Method Detail

setPxPyPzE

setPtEtaPhiM

eta

et2

et

mass

m

rapidity

mag

perp2

perp

setEnergy

compareTo

copy

toString

px

py

pz

getRapidity

getPt2

getPt

getPhi

getConstituentsList

setConstituents

addConstituent

getConstituents

phi

e

setPx

setPy

setPz

setRapidity

setPhi

setPt2

cachePhiRapidity

add

add

hashCode