gsl_root_stef Class Template Reference

#include <gsl_root_stef.h>


Detailed Description

template<class param_t, class func_t, class dfunc_t>
class gsl_root_stef< param_t, func_t, dfunc_t >

Steffenson equation solver (GSL).

This class finds a root of a function a derivative. If the derivative is not analytically specified, it is most likely preferable to use of the alternatives, gsl_root_brent, cern_root, or cern_mroot_root. The function solve_de() performs the solution automatically, and a lower-level GSL-like interface with set() and iterate() is also provided.

By default, this solver compares the present value of the root ($ root $) to the previous value ($ x $), and returns success if $ | root - x | < tol $, where $ tol = tolx + tolf2 root $.

If test_residual is set to true, then the solver additionally requires that the absolute value of the function is less than root::tolf.

The original variable x_2 has been removed as it was unused in the original GSL code.

Definition at line 57 of file gsl_root_stef.h.


Public Member Functions

 gsl_root_stef ()
virtual const char * type ()
 Return the type, "gsl_root_stef".
int iterate ()
 Perform an iteration.
virtual int solve_de (double &xx, param_t &pa, func_t &fun, dfunc_t &dfun)
 Solve func using x as an initial guess using derivatives df.
int set (func_t &fun, dfunc_t &dfun, double guess, param_t &pa)
 Set the information for the solver.

Data Fields

double root
 The present solution estimate.
double tolf2
 The relative tolerance for subsequent solutions (default $ 10^{-12} $).
bool test_residual
 True if we should test the residual also (default false).

Protected Attributes

double f
 Desc.
double df
 Desc.
double x_1
 Desc.
double x
 Desc.
int count
 Desc.
func_t * fp
 The function to solve.
dfunc_t * dfp
 The derivative.
param_t * params
 The function parameters.

Member Function Documentation

int iterate (  )  [inline]

Perform an iteration.

After a successful iteration, root contains the most recent value of the root.

Definition at line 111 of file gsl_root_stef.h.

int set ( func_t &  fun,
dfunc_t &  dfun,
double  guess,
param_t &  pa 
) [inline]

Set the information for the solver.

Set the function, the derivative, the initial guess and the parameters.

Definition at line 222 of file gsl_root_stef.h.


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

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