Clipper
Public Member Functions | Static Public Member Functions | List of all members
clipper::TargetFn_sigmaa_omegaa< T > Class Template Reference

#include <resol_targetfn.h>

Inheritance diagram for clipper::TargetFn_sigmaa_omegaa< T >:
clipper::TargetFn_base

Public Member Functions

 TargetFn_sigmaa_omegaa (const HKL_data< T > &eo, const HKL_data< T > &ec)
 constructor: takes the datalist against which to calc target
 
Rderiv rderiv (const HKL_info::HKL_reference_index &ih, const ftype &omegaa) const
 return the value and derivatives of the target function
 
- Public Member Functions inherited from clipper::TargetFn_base
virtual FNtype type () const
 the type of the function: optionally used to improve convergence
 
virtual ~TargetFn_base ()
 destructor
 
void debug (const HKL_info &hkl_info) const
 test that the residuals, gradients, and curvatures are consistent
 

Static Public Member Functions

static ftype sigmaa (const ftype &omegaa)
 convert omegaa to sigmaa
 

Additional Inherited Members

- Public Types inherited from clipper::TargetFn_base
enum  FNtype { GENERAL, QUADRATIC }
 enumeration of function types: optionally used to improve convergence
 

Detailed Description

template<class T>
class clipper::TargetFn_sigmaa_omegaa< T >

Deprecated:
simple sigma_a target function

This class implements the target function for calculating sigma_a. Required is a datalist containing Eo, Ec.

It actually refines omegaa = sigmaa/(1-sigmaa^2). This has better proerties for refinement. To get sigmaa use

sigmaa = ( sqrt( 4*omegaa^2 + 1 ) - 1 ) / ( 2*omegaa )

This is available as a static function:

sigmaa = targetfn.sigmaa( omegaa )

This version simplifies terms in |Eo|^2 and |Ec|^2 which should average out to 1 if the normalisation scheme is consistent with the sigmaa calc.

Convergence is good for calculations using the 'binner' basis function, however the smooth basis function have convergence problems. This is still under investigation.


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