QuantLib
A free/open-source library for quantitative finance
Reference manual - version 1.20
Public Member Functions | List of all members
SquareRootProcess Class Reference

Square-root process class. More...

#include <ql/processes/squarerootprocess.hpp>

+ Inheritance diagram for SquareRootProcess:

Public Member Functions

 SquareRootProcess (Real b, Real a, Volatility sigma, Real x0=0.0, const ext::shared_ptr< discretization > &d=ext::shared_ptr< discretization >(new EulerDiscretization))
 
- Public Member Functions inherited from StochasticProcess1D
virtual Real expectation (Time t0, Real x0, Time dt) const
 
virtual Real stdDeviation (Time t0, Real x0, Time dt) const
 
virtual Real variance (Time t0, Real x0, Time dt) const
 
virtual Real evolve (Time t0, Real x0, Time dt, Real dw) const
 
virtual Real apply (Real x0, Real dx) const
 
- Public Member Functions inherited from StochasticProcess
virtual Size factors () const
 returns the number of independent factors of the process
 
virtual Time time (const Date &) const
 
void update ()
 
- Public Member Functions inherited from Observer
 Observer (const Observer &)
 
Observeroperator= (const Observer &)
 
std::pair< iterator, bool > registerWith (const ext::shared_ptr< Observable > &)
 
void registerWithObservables (const ext::shared_ptr< Observer > &)
 
Size unregisterWith (const ext::shared_ptr< Observable > &)
 
void unregisterWithAll ()
 
virtual void deepUpdate ()
 
- Public Member Functions inherited from Observable
 Observable (const Observable &)
 
Observableoperator= (const Observable &)
 
void notifyObservers ()
 

StochasticProcess interface

Real x0 () const
 returns the initial value of the state variable
 
Real drift (Time t, Real x) const
 returns the drift part of the equation, i.e. \( \mu(t, x_t) \)
 
Real diffusion (Time t, Real x) const
 returns the diffusion part of the equation, i.e. \( \sigma(t, x_t) \)
 
Real a () const
 
Real b () const
 
Real sigma () const
 

Additional Inherited Members

- Public Types inherited from Observer
typedef boost::unordered_set< ext::shared_ptr< Observable > > set_type
 
typedef set_type::iterator iterator
 
- Protected Member Functions inherited from StochasticProcess1D
 StochasticProcess1D ()
 
 StochasticProcess1D (const ext::shared_ptr< discretization > &)
 
- Protected Member Functions inherited from StochasticProcess
 StochasticProcess ()
 
 StochasticProcess (const ext::shared_ptr< discretization > &)
 
- Protected Attributes inherited from StochasticProcess1D
ext::shared_ptr< discretizationdiscretization_
 
- Protected Attributes inherited from StochasticProcess
ext::shared_ptr< discretizationdiscretization_
 

Detailed Description

Square-root process class.

This class describes a square-root process governed by

\[ dx = a (b - x_t) dt + \sigma \sqrt{x_t} dW_t. \]