ContactCenters
V. 0.9.9.

umontreal.iro.lecuyer.contactcenters.contact
Class PoissonArrivalProcessWithRandomRates

java.lang.Object
  extended by umontreal.iro.lecuyer.contactcenters.contact.ContactArrivalProcess
      extended by umontreal.iro.lecuyer.contactcenters.contact.PoissonArrivalProcess
          extended by umontreal.iro.lecuyer.contactcenters.contact.PiecewiseConstantPoissonArrivalProcess
              extended by umontreal.iro.lecuyer.contactcenters.contact.PoissonArrivalProcessWithRandomRates
All Implemented Interfaces:
ContactSource, Initializable, Named, PeriodChangeListener, ToggleElement

public class PoissonArrivalProcessWithRandomRates
extends PiecewiseConstantPoissonArrivalProcess

Represents a poisson arrival process with piecewise-constant randomized arrival rates following a user-defined distribution. When constructing an arrival process of this type, one gives a specific random variate generator for each period. The arrival rates are generated independently for each period, each time the process is initialized.


Field Summary
 
Fields inherited from class umontreal.iro.lecuyer.contactcenters.contact.PiecewiseConstantPoissonArrivalProcess
busyGen, s_bgammaParam, s_numMC, varianceEpsilon
 
Fields inherited from class umontreal.iro.lecuyer.contactcenters.contact.ContactArrivalProcess
contactEvent
 
Constructor Summary
PoissonArrivalProcessWithRandomRates(PeriodChangeEvent pce, ContactFactory factory, RandomVariateGen[] genLambdas, RandomStream stream)
          Constructs a new Poisson-gamma arrival process using factory to instantiate contacts.
 
Method Summary
 double getExpectedArrivalRate(double st, double et)
          Determines the expected mean arrival rate in time interval [s, e] for this arrival process assuming that the expected value of the busyness factor is 1.
 double getExpectedArrivalRate(int p)
          Determines the expected arrival rate in period p for this arrival process assuming that the expected value of the busyness factor is 1.
 RandomVariateGen[] getRateGenerators()
          Returns the random variate generators for the arrival rates..
 void init()
          Initializes the new arrival process.
 void setRateGenerators(RandomVariateGen[] genLambdas)
          Sets the random variate generators for the arrival rates to genLambdas.
 
Methods inherited from class umontreal.iro.lecuyer.contactcenters.contact.PiecewiseConstantPoissonArrivalProcess
changePeriod, getArrivalRate, getArrivalRate, getInstanceFromMLE, getLambdas, getMLE, getMLENegMulti, getNumMC, getPeriodChangeEvent, getVarianceEpsilon, isNormalizing, setLambdas, setNormalizing, setNumMC, setVarianceEpsilon, startStationary, stop, toString
 
Methods inherited from class umontreal.iro.lecuyer.contactcenters.contact.PoissonArrivalProcess
clearCache, getGenWithCache, getInstanceFromMLE, getLambda, getStream, initCache, isCaching, nextTime, setCaching, setLambda, setStream
 
Methods inherited from class umontreal.iro.lecuyer.contactcenters.contact.ContactArrivalProcess
addNewContactListener, clearNewContactListeners, getArrivalRates, getBusynessFactor, getContactFactory, getExpectedArrivalRateB, getExpectedArrivalRateB, getExpectedArrivalRates, getExpectedArrivalRatesB, getExpectedBusynessFactor, getName, getNewContactListeners, getNextArrivalTime, init, isStarted, notifyNewContact, removeNewContactListener, setBusynessFactor, setContactFactory, setExpectedBusynessFactor, setName, setSimulator, simulator, start, start, stop
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

PoissonArrivalProcessWithRandomRates

public PoissonArrivalProcessWithRandomRates(PeriodChangeEvent pce,
                                            ContactFactory factory,
                                            RandomVariateGen[] genLambdas,
                                            RandomStream stream)
Constructs a new Poisson-gamma arrival process using factory to instantiate contacts. For each period p, the parameters of the random rate are given in genLambdas[p]. The random stream stream is used to generate the uniforms for the exponential times.

Parameters:
pce - the period-change event associated with this object.
factory - the factory creating contacts for this generator.
genLambdas - the random variate generators, for each period.
stream - random number stream for the exponential variates.
Throws:
IllegalArgumentException - if there is not one generator for each period.
NullPointerException - if any argument is null.
Method Detail

getRateGenerators

public RandomVariateGen[] getRateGenerators()
Returns the random variate generators for the arrival rates..

Returns:
the random variate generators for the arrival rates.

setRateGenerators

public void setRateGenerators(RandomVariateGen[] genLambdas)
Sets the random variate generators for the arrival rates to genLambdas.

Parameters:
genLambdas - the random variate generators, for each period.
Throws:
NullPointerException - if genLambdas is null.
IllegalArgumentException - if the length of the given array does not correspond to at least the number of periods.

getExpectedArrivalRate

public double getExpectedArrivalRate(int p)
Description copied from class: ContactArrivalProcess
Determines the expected arrival rate in period p for this arrival process assuming that the expected value of the busyness factor is 1. The arrival rate corresponds to the expected number of arrivals per simulation time unit during the specified period; one must multiply the rate by the period duration to get the expected number of arrivals during the period. If arrival rates are deterministic, this returns the same value as ContactArrivalProcess.getArrivalRate(int).

If $ \E$[B]≠1, one should use ContactArrivalProcess.getExpectedArrivalRateB(int) which takes the expectation of the busyness factor into account.

If the expected arrival rate is not available, throws an UnsupportedOperationException. This is the default behavior of this method if not overridden by a subclass.

Overrides:
getExpectedArrivalRate in class PiecewiseConstantPoissonArrivalProcess
Parameters:
p - the queried period index.
Returns:
the expected arrival rate in that period.

getExpectedArrivalRate

public double getExpectedArrivalRate(double st,
                                     double et)
Description copied from class: ContactArrivalProcess
Determines the expected mean arrival rate in time interval [s, e] for this arrival process assuming that the expected value of the busyness factor is 1. The arrival rate corresponds to the expected number of arrivals per simulation time unit during the specified interval; one must multiply the rate by the interval length to get the expected number of arrivals during the interval. If arrival rates are deterministic, this returns the same value as ContactArrivalProcess.getArrivalRate(double,double). If λ(t) is the arrival rate at time t, this method returns

$\displaystyle \htint_{s}^{e}$$\displaystyle \E$[λ(t)]dt/(e - s).

If $ \E$[B]≠1, one should use ContactArrivalProcess.getExpectedArrivalRateB(double,double) which takes the expectation of the busyness factor into account.

This method returns 0 if es.

If the expected arrival rate is not available, throws an UnsupportedOperationException. This is the default behavior of this method if not overridden by a subclass.

Overrides:
getExpectedArrivalRate in class PiecewiseConstantPoissonArrivalProcess
Parameters:
st - the starting time s.
et - the ending time e.
Returns:
the expected arrival rate in the given time interval.

init

public void init()
Description copied from class: ContactArrivalProcess
Initializes the new arrival process. If this method is overridden by a subclass, it is important to call super.init() in order to ensure that everything is initialized correctly.

Specified by:
init in interface ContactSource
Specified by:
init in interface Initializable
Overrides:
init in class PiecewiseConstantPoissonArrivalProcess

ContactCenters
V. 0.9.9.

To submit a bug or ask questions, send an e-mail to Richard Simard.