SSJ  3.3.1
Stochastic Simulation in Java
Public Member Functions | List of all members
VarianceGammaProcessAlternate Class Reference

This is a VarianceGammaProcess for which the successive random numbers are used in a different order to generate the sample path. More...

Inheritance diagram for VarianceGammaProcessAlternate:
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Collaboration diagram for VarianceGammaProcessAlternate:
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Public Member Functions

 VarianceGammaProcessAlternate (double s0, double theta, double sigma, double nu, RandomStream stream)
 
 VarianceGammaProcessAlternate (double s0, BrownianMotion BM, GammaProcess Gamma)
 
double [] generatePath ()
 Generates the sample path by using the uniform random numbers in an alternate way, and returns the path of the VG process.
 
- Public Member Functions inherited from VarianceGammaProcess
 VarianceGammaProcess (double s0, double theta, double sigma, double nu, RandomStream stream)
 Constructs a new VarianceGammaProcess with parameters \(\theta= \mathtt{theta}\), \(\sigma= \mathtt{sigma}\), \(\nu= \mathtt{nu}\) and initial value \(S(t_0) = \mathtt{s0}\). More...
 
 VarianceGammaProcess (double s0, BrownianMotion BM, GammaProcess Gamma)
 Constructs a new VarianceGammaProcess. More...
 
double nextObservation ()
 Generates the observation for the next time. More...
 
double [] generatePath ()
 Generates and returns the path. More...
 
double [] generatePath (double[] uniform01)
 Similar to the usual generatePath(), but here the uniform random numbers used for the simulation must be provided to the method. More...
 
void resetStartProcess ()
 Resets the observation index and counter to 0 and applies the resetStartProcess method to the BrownianMotion and the GammaProcess objects used to generate this process.
 
void setParams (double s0, double theta, double sigma, double nu)
 Sets the parameters \(S(t_0) =\) s0, \(\theta=\) theta, \(\sigma=\) sigma and \(\nu=\) nu of the process. More...
 
double getTheta ()
 Returns the value of the parameter \(\theta\).
 
double getSigma ()
 Returns the value of the parameter \(\sigma\).
 
double getNu ()
 Returns the value of the parameter \(\nu\).
 
void setObservationTimes (double t[], int d)
 Sets the observation times on the VarianceGammaProcess as usual, but also sets the observation times of the underlying GammaProcess. More...
 
void setStream (RandomStream stream)
 Resets the umontreal.ssj.rng.RandomStream ’s. More...
 
RandomStream getStream ()
 Returns the random stream of the BrownianMotion process, which should be the same as for the GammaProcess.
 
BrownianMotion getBrownianMotion ()
 Returns a reference to the inner BrownianMotion.
 
GammaProcess getGammaProcess ()
 Returns a reference to the inner GammaProcess.
 
- Public Member Functions inherited from StochasticProcess
void setObservationTimes (double[] T, int d)
 Sets the observation times of the process to a copy of T, with. More...
 
void setObservationTimes (double delta, int d)
 Sets equidistant observation times at \(t_j = j\delta\), for. More...
 
double [] getObservationTimes ()
 Returns a reference to the array that contains the observation times. More...
 
int getNumObservationTimes ()
 Returns the number \(d\) of observation times, excluding the time \(t_0\).
 
abstract double [] generatePath ()
 Generates, returns, and saves the sample path \(\{X(t_0), X(t_1), \dots, X(t_d)\}\). More...
 
double [] generatePath (RandomStream stream)
 Same as generatePath(), but first resets the stream to stream.
 
double [] getPath ()
 Returns a reference to the last generated sample path \(\{X(t_0), ... , X(t_d)\}\). More...
 
void getSubpath (double[] subpath, int[] pathIndices)
 Returns in subpath the values of the process at a subset of the observation times, specified as the times \(t_j\) whose indices. More...
 
double getObservation (int j)
 Returns \(X(t_j)\) from the current sample path. More...
 
void resetStartProcess ()
 Resets the observation counter to its initial value \(j=0\), so that the current observation \(X(t_j)\) becomes \(X(t_0)\). More...
 
boolean hasNextObservation ()
 Returns true if \(j<d\), where \(j\) is the number of observations of the current sample path generated since the last call to resetStartProcess. More...
 
double nextObservation ()
 Generates and returns the next observation \(X(t_j)\) of the stochastic process. More...
 
int getCurrentObservationIndex ()
 Returns the value of the index \(j\) corresponding to the time. More...
 
double getCurrentObservation ()
 Returns the value of the last generated observation \(X(t_j)\).
 
double getX0 ()
 Returns the initial value \(X(t_0)\) for this process.
 
void setX0 (double s0)
 Sets the initial value \(X(t_0)\) for this process to s0, and reinitializes.
 
abstract void setStream (RandomStream stream)
 Resets the random stream of the underlying generator to stream.
 
abstract RandomStream getStream ()
 Returns the random stream of the underlying generator.
 
int [] getArrayMappingCounterToIndex ()
 Returns a reference to an array that maps an integer \(k\) to \(i_k\), the index of the observation \(S(t_{i_k})\) corresponding to the \(k\)-th observation to be generated for a sample path of this process. More...
 

Additional Inherited Members

- Protected Member Functions inherited from VarianceGammaProcess
void init ()
 
- Protected Member Functions inherited from StochasticProcess
void init ()
 
- Protected Attributes inherited from VarianceGammaProcess
GammaProcess randomTime
 
BrownianMotion BM
 
double theta
 
- Protected Attributes inherited from StochasticProcess
boolean observationTimesSet = false
 
double x0 = 0.0
 
int d = -1
 
int observationIndex = 0
 
int observationCounter = 0
 
double [] t
 
double [] path
 
int [] observationIndexFromCounter
 
- Package Attributes inherited from VarianceGammaProcess
double sigma
 
double nu
 

Detailed Description

This is a VarianceGammaProcess for which the successive random numbers are used in a different order to generate the sample path.

The first one is used for the first generated value of the gamma process, the second one for the first generated value of the Brownian process, the third one for the second generated value of the gamma process, the fourth one for the second value of the Brownian process, and so on. Only the order in which the uniform random numbers are used in the method generatePath differs. These numbers are generated at the beginning and then reordered. This can make a difference when we use RQMC methods.


The documentation for this class was generated from the following file: