SquareRootProcess Class Reference
Stochastic processes

Square-root process class. More...

`#include <ql/processes/squarerootprocess.hpp>`

Inheritance diagram for SquareRootProcess:
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## Public Member Functions

| SquareRootProcess (Real b, Real a, Volatility sigma, Real x0=0.0, const boost::shared_ptr< discretization > &d=boost::shared_ptr< discretization >(new EulerDiscretization))
Real | a () const
Real | b () const
Real | sigma () const
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. \( \sigma(t, x_t) \)
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 &)
Observer & | operator= (const Observer &)
std::pair< iterator, bool > | registerWith (const boost::shared_ptr< Observable > &)
void | registerWithObservables (const boost::shared_ptr< Observer > &)
Size | unregisterWith (const boost::shared_ptr< Observable > &)
void | unregisterWithAll ()
virtual void | deepUpdate ()
Public Member Functions inherited from Observable
| Observable (const Observable &)
Observable & | operator= (const Observable &)
void | notifyObservers ()

## Additional Inherited Members

Public Types inherited from Observer
typedef std::set< boost::shared_ptr< Observable > > | set_type
typedef set_type::iterator | iterator
Protected Member Functions inherited from StochasticProcess1D
| StochasticProcess1D (const boost::shared_ptr< discretization > &)
Protected Member Functions inherited from StochasticProcess
| StochasticProcess (const boost::shared_ptr< discretization > &)
Protected Attributes inherited from StochasticProcess1D
boost::shared_ptr< discretization > | discretization_
Protected Attributes inherited from StochasticProcess
boost::shared_ptr< discretization > | discretization_

## Detailed Description

Square-root process class.

This class describes a square-root process governed by

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