RealQuadEquation Struct Reference

#include <RealQuadEquation.h>

Public Member Functions
	RealQuadEquation (double A, double B, double C)

Public Attributes
double	first
bool	hasSolution
double	second

Detailed Description

A numericaly stable and as fast as can be quadratic equation solver. The equation has the form A*x^2 + B*x + C = 0

Definition at line 11 of file RealQuadEquation.h.

Constructor & Destructor Documentation

RealQuadEquation()

RealQuadEquation::RealQuadEquation ( double  A, double  B, double  C  )

inline

Definition at line 16 of file RealQuadEquation.h.

                                                 {
    double D = B * B - 4 * A * C;
    if (D < 0)
      hasSolution = false;
    else {
      hasSolution = true;
      auto q = -0.5 * (B + std::copysign(std::sqrt(D), B));
      first = q / A;
      second = C / q;
    }
  }

References MaterialEffects_cfi::A, TtFullHadDaughter::B, gen::C, first, submitPVResolutionJobs::q, edm::second(), and mathSSE::sqrt().

Member Data Documentation

first

double RealQuadEquation::first

Definition at line 12 of file RealQuadEquation.h.

Referenced by HelixBarrelCylinderCrossing::HelixBarrelCylinderCrossing(), and HelixBarrelPlaneCrossingByCircle::pathLength().

hasSolution

bool RealQuadEquation::hasSolution

Definition at line 14 of file RealQuadEquation.h.

Referenced by HelixBarrelCylinderCrossing::HelixBarrelCylinderCrossing(), and HelixBarrelPlaneCrossingByCircle::pathLength().

second

double RealQuadEquation::second

Definition at line 13 of file RealQuadEquation.h.

Referenced by HelixBarrelCylinderCrossing::HelixBarrelCylinderCrossing(), and HelixBarrelPlaneCrossingByCircle::pathLength().