GaussianTail Class Reference

#include <GaussianTail.h>

Public Member Functions
	GaussianTail (double sigma=1., double threshold=2.)
void	setParameters (double sigma, double threshold)
double	shoot (RandomEngineAndDistribution const *) const
	~GaussianTail ()

Private Attributes
double	s_
double	sigma_
double	ssquare_
double	threshold_

Detailed Description

Definition at line 10 of file GaussianTail.h.

Constructor & Destructor Documentation

GaussianTail()

GaussianTail::GaussianTail	(	double	sigma = 1.,
		double	threshold = 2.
	)

Definition at line 5 of file GaussianTail.cc.

                                                         : sigma_(sigma), threshold_(threshold) {
  s_ = threshold_ / sigma_;
  ssquare_ = s_ * s_;
}

References s_, sigma_, ssquare_, and threshold_.

~GaussianTail()

GaussianTail::~GaussianTail

(

)

Definition at line 10 of file GaussianTail.cc.

{ ; }

Member Function Documentation

setParameters()

void GaussianTail::setParameters ( double  sigma, double  threshold  )

inline

Definition at line 14 of file GaussianTail.h.

                                                            {
    sigma_ = sigma;
    threshold_ = threshold;
    s_ = threshold_ / sigma_;
    ssquare_ = s_ * s_;
  };

References s_, sigma_, ssquare_, remoteMonitoring_LED_IterMethod_cfg::threshold, and threshold_.

shoot()

double GaussianTail::shoot

(

RandomEngineAndDistribution const *

random

)

const

Definition at line 12 of file GaussianTail.cc.

                                                                          {
  // in the zero suppresion case, s is usually >2
  if (s_ > 1.) {
    /* Use the "supertail" deviates from the last two steps
       * of Marsaglia's rectangle-wedge-tail method, as described
       * in Knuth, v2, 3rd ed, pp 123-128.  (See also exercise 11, p139,
       * and the solution, p586.)
       */
 
    double u, v, x;
 
    do {
      u = random->flatShoot();
      do {
        v = random->flatShoot();
      } while (v == 0.0);
      x = std::sqrt(ssquare_ - 2 * std::log(v));
    } while (x * u > s_);
    return x * sigma_;
  } else {
    /* For small s, use a direct rejection method. The limit s < 1
         can be adjusted to optimise the overall efficiency 
       */
 
    double x;
 
    do {
      x = random->gaussShoot();
    } while (x < s_);
    return x * sigma_;
  }
}

References RandomEngineAndDistribution::flatShoot(), RandomEngineAndDistribution::gaussShoot(), dqm-mbProfile::log, s_, sigma_, mathSSE::sqrt(), ssquare_, findQualityFiles::v, and x.

Member Data Documentation

s_

double GaussianTail::s_

private

Definition at line 25 of file GaussianTail.h.

Referenced by GaussianTail(), setParameters(), and shoot().

sigma_

double GaussianTail::sigma_

private

Definition at line 23 of file GaussianTail.h.

Referenced by GaussianTail(), setParameters(), and shoot().

ssquare_

double GaussianTail::ssquare_

private

Definition at line 26 of file GaussianTail.h.

Referenced by GaussianTail(), setParameters(), and shoot().

threshold_

double GaussianTail::threshold_

private

Definition at line 24 of file GaussianTail.h.

Referenced by GaussianTail(), and setParameters().