ChargedTracksWeightFilter::Spline Struct Reference

#include <ChargedTracksWeightFilter.h>

Collaboration diagram for ChargedTracksWeightFilter::Spline:

Classes
struct	Point
	Linear spline representation of a function used to calculate weights. More...

Public Member Functions
StatusCode	initialize (std::vector< double > &x, std::vector< double > &y)
double	get_minimum (double min, double max) const
	get minimum over certain range (requires initialization to extrapolate) More...
double	value (int nch) const
	get value for certain x More...

Public Attributes
std::vector< Point >	points
	n-1 spline points filled at initialization More...

Detailed Description

Definition at line 25 of file ChargedTracksWeightFilter.h.

Member Function Documentation

get_minimum()

double ChargedTracksWeightFilter::Spline::get_minimum	(	double	min,
		double	max
	)		const

get minimum over certain range (requires initialization to extrapolate)

Definition at line 229 of file ChargedTracksWeightFilter.cxx.

                                                                                {
  // evaluate minimum of the spline over a defined range
 
  // spline must be initialized
  if(points.empty()) return -1;
 
  const double dummy = -1;
 
  // if min, max are in between points, or extrapolation needed
  auto minimum = std::min(value(min), value(max));
 
  //  find boundary points and scan the allowed range
  auto min_item = std::lower_bound(points.begin(), points.end(), Point(min, dummy, dummy), comp_x);
  auto max_item = std::upper_bound(points.begin(), points.end(), Point(max, dummy, dummy), comp_x);
 
  if(min_item != max_item) {
    const auto smallest = std::min_element(min_item, max_item, comp_y);
    minimum = std::min(minimum, smallest-> y);
  }
 
  return minimum;
}

initialize()

StatusCode ChargedTracksWeightFilter::Spline::initialize	(	std::vector< double > &	x,
		std::vector< double > &	y
	)

Definition at line 252 of file ChargedTracksWeightFilter.cxx.

                                                                                                    {
 
  if(x.size() < 2 || x.size() != y.size()) {
    std::cout << "Spline not properly defined. SplineX, SplineY vectors are required to have at least 2 elements and same size.\n";
    return StatusCode::FAILURE;
  }
 
  // calculate slope terms
  for(size_t i=0; i< x.size()-1; i++){
 
    const auto & x0 = x[i];
    const auto & y0 = y[i];
    const auto & x1 = x[i+1];
    const auto & y1 = y[i+1];
 
    const auto dx = x1 - x0;
    const auto dy = y1 - y0;
 
    if(dx <=0) {
      std::cout << "Spline not properly defined. SplineX is required to be monotonically increasing.\n";
      return StatusCode::FAILURE;
    }
 
    points.push_back( Point(x[i], y[i], dy/dx));
  }
 
  return StatusCode::SUCCESS;
}

value()

double ChargedTracksWeightFilter::Spline::value

(

int

nch

)

const

get value for certain x

Definition at line 208 of file ChargedTracksWeightFilter.cxx.

                                                           {
 
  const double dummy = -1;
 
  // find lowest weight in allowed range
  auto lower = std::upper_bound(points.begin(), points.end(),
                                Point(nch, dummy, dummy), comp_x);
 
  if(lower != points.begin()) lower--;
 
  const auto & x = lower-> x;
  const auto & y = lower-> y;;
  const auto & slope = lower-> slope;;
 
  // weight using linear spline
  const auto w_fc = (nch-x)*slope + y;
 
  if(w_fc<0) return 0;   // extrapolation gives negative value
  else return w_fc;
}

Member Data Documentation

points

std::vector<Point> ChargedTracksWeightFilter::Spline::points

n-1 spline points filled at initialization

Definition at line 39 of file ChargedTracksWeightFilter.h.

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

• ChargedTracksWeightFilter.h
• ChargedTracksWeightFilter.cxx