| 1 |
#ifndef INC_ANGLESUTIL
|
| 2 |
#define INC_ANGLESUTIL
|
| 3 |
///////////////////////////////////////////////////////////////////////////////
|
| 4 |
// File: AnglesUtil.hpp
|
| 5 |
//
|
| 6 |
// Purpose: Provide useful functions for calculating angles and eta
|
| 7 |
//
|
| 8 |
// Created: 4-NOV-1998 Serban Protopopescu
|
| 9 |
// History: replaced old KinemUtil
|
| 10 |
// Modified: 23-July-2000 Add rapidity calculation
|
| 11 |
// 14-Aug-2003 converted all functions to double precision
|
| 12 |
///////////////////////////////////////////////////////////////////////////////
|
| 13 |
// Dependencies (#includes)
|
| 14 |
|
| 15 |
#include <cmath>
|
| 16 |
#include <cstdlib>
|
| 17 |
|
| 18 |
|
| 19 |
namespace kinem{
|
| 20 |
const double PI=2.0*acos(0.);
|
| 21 |
const double TWOPI=2.0*PI;
|
| 22 |
const float ETA_LIMIT=15.0;
|
| 23 |
const float EPSILON=1.E-10;
|
| 24 |
|
| 25 |
// calculate phi from x, y
|
| 26 |
inline double phi(double x, double y);
|
| 27 |
// calculate phi for a line defined by xy1 and xy2 (xy2-xy1)
|
| 28 |
inline double phi(double xy1[2], double xy2[2]);
|
| 29 |
inline double phi(float xy1[2], float xy2[2]);
|
| 30 |
|
| 31 |
// calculate theta from x, y, z
|
| 32 |
inline double theta(double x, double y, double z);
|
| 33 |
// calculate theta for a line defined by xyz1 and xyz2 (xyz2-xyz1)
|
| 34 |
inline double theta(double xyz1[3], double xyz2[3]);
|
| 35 |
inline double theta(float xyz1[3], float xyz2[3]);
|
| 36 |
// calculate theta from eta
|
| 37 |
inline double theta(double etap);
|
| 38 |
|
| 39 |
// calculate eta from x, y, z (return also theta)
|
| 40 |
inline double eta(double x, double y, double z);
|
| 41 |
// calculate eta for a line defined by xyz1 and xyz2 (xyz2-xyz1)
|
| 42 |
inline double eta(double xyz1[3], double xyz2[3]);
|
| 43 |
inline double eta(float xyz1[3], float xyz2[3]);
|
| 44 |
// calculate eta from theta
|
| 45 |
inline double eta(double th);
|
| 46 |
|
| 47 |
// calculate rapidity from E, pz
|
| 48 |
inline double y(double E, double pz);
|
| 49 |
|
| 50 |
// calculate phi1-phi2 keeping value between 0 and pi
|
| 51 |
inline double delta_phi(double ph11, double phi2);
|
| 52 |
// calculate phi1-phi2 keeping value between -pi and pi
|
| 53 |
inline double signed_delta_phi(double ph11, double phi2);
|
| 54 |
// calculate deltaR
|
| 55 |
inline double delta_R(double eta1, double phi1, double eta2, double phi2);
|
| 56 |
|
| 57 |
// calculate unit vectors given two points
|
| 58 |
inline void uvectors(double u[3], double xyz1[3], double xyz2[3]);
|
| 59 |
inline void uvectors(float u[3], float xyz1[3], float xyz2[3]);
|
| 60 |
|
| 61 |
inline double tanl_from_theta(double theta);
|
| 62 |
inline double theta_from_tanl(double tanl);
|
| 63 |
}
|
| 64 |
|
| 65 |
inline
|
| 66 |
double kinem::phi(double x, double y)
|
| 67 |
{
|
| 68 |
double PHI=atan2(y, x);
|
| 69 |
return (PHI>=0)? PHI : kinem::TWOPI+PHI;
|
| 70 |
}
|
| 71 |
|
| 72 |
inline
|
| 73 |
double kinem::phi(float xy1[2], float xy2[2]){
|
| 74 |
double dxy1[2]={xy1[0],xy1[1]};
|
| 75 |
double dxy2[2]={xy2[0],xy2[1]};
|
| 76 |
return phi(dxy1,dxy2);
|
| 77 |
}
|
| 78 |
|
| 79 |
inline
|
| 80 |
double kinem::phi(double xy1[2], double xy2[2])
|
| 81 |
{
|
| 82 |
double x=xy2[0]-xy1[0];
|
| 83 |
double y=xy2[1]-xy1[1];
|
| 84 |
return phi(x, y);
|
| 85 |
}
|
| 86 |
|
| 87 |
inline
|
| 88 |
double kinem::delta_phi(double phi1, double phi2)
|
| 89 |
{
|
| 90 |
double PHI=fabs(phi1-phi2);
|
| 91 |
return (PHI<=PI)? PHI : kinem::TWOPI-PHI;
|
| 92 |
}
|
| 93 |
|
| 94 |
inline
|
| 95 |
double kinem::signed_delta_phi(double phi1, double phi2)
|
| 96 |
{
|
| 97 |
double phia=phi1;
|
| 98 |
if(phi1>PI) phia=phi1-kinem::TWOPI;
|
| 99 |
double phib=phi2;
|
| 100 |
if(phi2>PI) phib=phi2-kinem::TWOPI;
|
| 101 |
double dphi=phia-phib;
|
| 102 |
if(dphi>PI) dphi-=kinem::TWOPI;
|
| 103 |
if(dphi<-PI) dphi+=kinem::TWOPI;
|
| 104 |
return dphi;
|
| 105 |
}
|
| 106 |
|
| 107 |
inline double kinem::delta_R(double eta1, double phi1, double eta2, double phi2)
|
| 108 |
{
|
| 109 |
double deta = eta1-eta2;
|
| 110 |
double dphi = kinem::delta_phi(phi1,phi2);
|
| 111 |
return sqrt(deta*deta + dphi*dphi);
|
| 112 |
}
|
| 113 |
|
| 114 |
inline
|
| 115 |
double kinem::theta(double xyz1[3], double xyz2[3])
|
| 116 |
{
|
| 117 |
double x=xyz2[0]-xyz1[0];
|
| 118 |
double y=xyz2[1]-xyz1[1];
|
| 119 |
double z=xyz2[2]-xyz1[2];
|
| 120 |
return theta(x, y, z);
|
| 121 |
}
|
| 122 |
|
| 123 |
inline
|
| 124 |
double kinem::theta(float xyz1[3], float xyz2[3]){
|
| 125 |
double dxyz1[3]={xyz1[0],xyz1[1],xyz1[2]};
|
| 126 |
double dxyz2[3]={xyz2[0],xyz2[1],xyz2[2]};
|
| 127 |
return theta(dxyz1,dxyz2);
|
| 128 |
}
|
| 129 |
|
| 130 |
inline
|
| 131 |
double kinem::theta(double x, double y, double z)
|
| 132 |
{
|
| 133 |
return atan2(sqrt(x*x + y*y), z);
|
| 134 |
}
|
| 135 |
|
| 136 |
inline
|
| 137 |
double kinem::theta(double etap)
|
| 138 |
{
|
| 139 |
return 2.0*atan(exp(-etap));
|
| 140 |
}
|
| 141 |
|
| 142 |
inline
|
| 143 |
double kinem::eta(double xyz1[3], double xyz2[3])
|
| 144 |
{
|
| 145 |
double x=xyz2[0]-xyz1[0];
|
| 146 |
double y=xyz2[1]-xyz1[1];
|
| 147 |
double z=xyz2[2]-xyz1[2];
|
| 148 |
return eta(x, y, z);
|
| 149 |
}
|
| 150 |
|
| 151 |
inline
|
| 152 |
double kinem::eta(float xyz1[3], float xyz2[3]){
|
| 153 |
double dxyz1[3]={xyz1[0],xyz1[1],xyz1[2]};
|
| 154 |
double dxyz2[3]={xyz2[0],xyz2[1],xyz2[2]};
|
| 155 |
return eta(dxyz1,dxyz2);
|
| 156 |
}
|
| 157 |
|
| 158 |
inline
|
| 159 |
double kinem::eta(double x, double y, double z)
|
| 160 |
{
|
| 161 |
return 0.5*log((sqrt(x*x + y*y + z*z) + z + EPSILON) /
|
| 162 |
(sqrt(x*x + y*y + z*z) - z + EPSILON));
|
| 163 |
}
|
| 164 |
|
| 165 |
inline
|
| 166 |
double kinem::eta(double th)
|
| 167 |
{
|
| 168 |
if(th == 0) return ETA_LIMIT;
|
| 169 |
if(th >= PI-0.0001) return -ETA_LIMIT;
|
| 170 |
return -log(tan(th/2.0));
|
| 171 |
}
|
| 172 |
|
| 173 |
inline
|
| 174 |
double kinem::y(double E, double pz)
|
| 175 |
{
|
| 176 |
return 0.5 * log ((E+pz+EPSILON)/(E-pz+EPSILON));
|
| 177 |
}
|
| 178 |
|
| 179 |
inline
|
| 180 |
void kinem::uvectors(double u[3], double xyz1[3], double xyz2[3]){
|
| 181 |
double xdiff=xyz2[0]-xyz1[0];
|
| 182 |
double ydiff=xyz2[1]-xyz1[1];
|
| 183 |
double zdiff=xyz2[2]-xyz1[2];
|
| 184 |
double s=sqrt(xdiff*xdiff+ydiff*ydiff+zdiff*zdiff);
|
| 185 |
if(s > 0) {
|
| 186 |
u[0]=xdiff/s;
|
| 187 |
u[1]=ydiff/s;
|
| 188 |
u[2]=zdiff/s;
|
| 189 |
}else{
|
| 190 |
u[0]=0;
|
| 191 |
u[1]=0;
|
| 192 |
u[2]=0;
|
| 193 |
}
|
| 194 |
}
|
| 195 |
|
| 196 |
inline
|
| 197 |
void kinem::uvectors(float u[3], float xyz1[3], float xyz2[3]){
|
| 198 |
double du[3];
|
| 199 |
double dxyz1[3]={xyz1[0],xyz1[1],xyz1[2]};
|
| 200 |
double dxyz2[3]={xyz2[0],xyz2[1],xyz2[2]};
|
| 201 |
uvectors(du,dxyz1,dxyz2);
|
| 202 |
u[0]=du[0];
|
| 203 |
u[1]=du[1];
|
| 204 |
u[2]=du[2];
|
| 205 |
}
|
| 206 |
|
| 207 |
inline
|
| 208 |
double kinem::tanl_from_theta(double theta){
|
| 209 |
return tan(PI/2.0 - theta);
|
| 210 |
}
|
| 211 |
|
| 212 |
inline
|
| 213 |
double kinem::theta_from_tanl(double tanl){
|
| 214 |
return PI/2.0 - atan(tanl);
|
| 215 |
}
|
| 216 |
|
| 217 |
#endif // INC_ANGLESUTIL
|
