1D Newton simple scheme More...

#include <benchmarkUtil.h>

Collaboration diagram for olb::util::Newton1D< T >:

Public Member Functions
	Newton1D (AnalyticalF1D< T, T > &f, T yValue=T(), T eps=1.e-8, int maxIterations=100)

T	solve (T startValue, bool print=false)

Protected Attributes
AnalyticalF1D< T, T > &	_f

AnalyticalDerivativeFD1D< T >	_df

T	_yValue

T	_eps

int	_maxIterations

Detailed Description

template<typename T>
class olb::util::Newton1D< T >

1D Newton simple scheme

Definition at line 124 of file benchmarkUtil.h.

Constructor & Destructor Documentation

◆ Newton1D()

template<typename T >

olb::util::Newton1D< T >::Newton1D	(	AnalyticalF1D< T, T > &	f,
		T	yValue = T(),
		T	eps = 1.e-8,
		int	maxIterations = 100 )

Definition at line 273 of file benchmarkUtil.hh.

                                                                               : _f(f), _df(f,eps), _yValue(yValue), _eps(eps), _maxIterations(maxIterations)
{
}

Member Function Documentation

◆ solve()

template<typename T >

T olb::util::Newton1D< T >::solve	(	T	startValue,
		bool	print = false )

Definition at line 278 of file benchmarkUtil.hh.

{
  T fValue[1], dfValue[1], x[1];
  x[0] = startValue;
  _f(fValue,x);
  T eps = util::fabs(fValue[0] - _yValue);
  for (int i=0; i<_maxIterations && eps>_eps; i++) {
    _f(fValue,x);
    _df(dfValue,x);
    eps = util::fabs(fValue[0] - _yValue);
    if (print) {
      std::cout << "newtonStep=" << i << "; eps=" << eps << "; x=" << x[0]  << "; f(x)="<< fValue[0] << "; df(x)="<< dfValue[0] << std::endl;
    }
    x[0] -= (fValue[0] - _yValue)/dfValue[0];
  }
  return x[0];
}