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ConstrainedOptPack::DirectLineSearchArmQuad_Strategy Class Reference

Performs a line search using the Armijo condition and uses quadratic interpolation to select each new alpha. More...

#include <ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.hpp>

Inheritance diagram for ConstrainedOptPack::DirectLineSearchArmQuad_Strategy:

[legend]
List of all members.

Overridden from DirectLineSearch_Strategy

void set_max_iter (int max_iter)
 
int max_iter () const
 
int num_iterations () const
 
bool do_line_search (const MeritFuncCalc1D &phi, value_type phi_k, value_type *alpha_k, value_type *phi_kp1, std::ostream *out)
 Performs the following line search:.
void print_algorithm (std::ostream &out, const std::string &leading_str) const
 

Public Member Functions

void eta (const value_type &eta)
 Set the Armijo cord test fractional reduction parameter.
void min_frac (const value_type &min_frac)
 The minimum fraction that alpha is reduced for each line search iteration.
void max_frac (const value_type &max_frac)
 The maximum fraction that alpha is reduced for each line search iteration.
void max_out_iter (const bool &max_out_iter)
 Deterimine if the line search iterations are maxed out or not.
 DirectLineSearchArmQuad_Strategy (int max_iter=20, value_type eta=1.0e-4, value_type min_frac=0.1, value_type max_frac=0.5, bool max_out_iter=false)
 Constructs with default settings.

Detailed Description

Performs a line search using the Armijo condition and uses quadratic interpolation to select each new alpha.

Definition at line 40 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.hpp.

Constructor & Destructor Documentation

ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::DirectLineSearchArmQuad_Strategy (  int  max_iter = 20,
value_type  eta = 1.0e-4,
value_type  min_frac = 0.1,
value_type  max_frac = 0.5,
bool  max_out_iter = false
) 
 

Constructs with default settings.

Definition at line 46 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.cpp.

Member Function Documentation

void ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::eta (  const value_type &  eta  )  [inline]
 

Set the Armijo cord test fractional reduction parameter.

Definition at line 44 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.hpp.

void ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::min_frac (  const value_type &  min_frac  )  [inline]
 

The minimum fraction that alpha is reduced for each line search iteration.

Definition at line 47 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.hpp.

void ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::max_frac (  const value_type &  max_frac  )  [inline]
 

The maximum fraction that alpha is reduced for each line search iteration.

Definition at line 50 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.hpp.

void ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::max_out_iter (  const bool &  max_out_iter  )  [inline]
 

Deterimine if the line search iterations are maxed out or not.

This option is really only used for debugging and requires changing the other parameters to make it useful.

Definition at line 57 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.hpp.

void ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::set_max_iter (  int  max_iter  )  [virtual]
 

Implements ConstrainedOptPack::DirectLineSearch_Strategy.

Definition at line 60 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.cpp.

int ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::max_iter (   )  const [virtual]
 

Implements ConstrainedOptPack::DirectLineSearch_Strategy.

Definition at line 65 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.cpp.

int ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::num_iterations (   )  const [virtual]
 

Implements ConstrainedOptPack::DirectLineSearch_Strategy.

Definition at line 70 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.cpp.

bool ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::do_line_search (  const MeritFuncCalc1D &  phi,
value_type  phi_k,
value_type *  alpha_k,
value_type *  phi_kp1,
std::ostream *  out
)  [virtual]
 

Performs the following line search:. 


   num_iter = 0;
   while( phi.value(alpha_k) > phi_k + eta * alpha_k * phi.deriv() ) 
   {
      if(num_iter >= max_iter) return true;
      num_iter = num_iter + 1;
      alpha_k = [ min_frac * alpha_k <= quadradic interpolation for alpha	<= max_frac * alpha_k ];
   }
   return true;<br>
If the maximum number of iterations is exceeded then false will be returned.

The default values for the adjustable parameters (from D&S A6.3.1) are:
max_iter = 20
eta = 1.0e-4
min_frac = 0.1
max_frac = 0.5

Implements ConstrainedOptPack::DirectLineSearch_Strategy.

Definition at line 75 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.cpp.

void ConstrainedOptPack::DirectLineSearchArmQuad_Strategy::print_algorithm (  std::ostream &  out,
const std::string &  leading_str
)  const [virtual]
 

Reimplemented from ConstrainedOptPack::DirectLineSearch_Strategy.

Definition at line 201 of file ConstrainedOptPack_DirectLineSearchArmQuad_Strategy.cpp.

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