NcStokes.cxx

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#include "NcStokes.h"
#include "Riostream.h"
 
ClassImp(NcStokes); // Class implementation to enable ROOT I/O
 
NcStokes::NcStokes()
{
 
 fI=0;
 fQ=0;
 fU=0;
 fV=0;
}

NcStokes::~NcStokes()
{
}

NcStokes::NcStokes(const NcStokes& q)
{
 
 fI=q.fI;
 fQ=q.fQ;
 fU=q.fU;
 fV=q.fV;
}

void NcStokes::SetStokesParameters(Double_t I,Double_t Q,Double_t U,Double_t V)
{
 
 if (I<=0)
 {
  cout << " *NcStokes::SetStokesParameters* Inconsistent data." << endl;
  cout << " I=" << fI << " Q=" << fQ << " U=" << fU << " V=" << fV << endl;
  return;
 }
 
 fI=I;
 fQ=Q;
 fU=U;
 fV=V;
}

void NcStokes::SetEllipseParameters(Double_t a,Double_t b,Double_t theta,TString u,Int_t h,Double_t p)
{
 
 fI=0;
 fQ=0;
 fU=0;
 fV=0;
 
 if (a<0 || b<0 || p<=0)
 {
  cout << " *NcStokes::SetEllipseParameters* Inconsistent input." << endl;
  cout << " a:" << a << " b:" << b << " theta:" << theta << " " << u << ". h:" << h << " p:" << p << endl;
  return;
 }
 
 Double_t pi=acos(-1.);
 
 if (u=="deg") theta*=pi/180.;
 
 Double_t a2=a*a;
 Double_t b2=b*b;
 
 fI=(a2+b2)/p;
 fQ=(a2-b2)*cos(2.*theta);
 fU=(a2-b2)*sin(2.*theta);
 fV=2.*a*b;
 if (h<0) fV=-fV;
}

void NcStokes::SetJonesVector(Double_t A1,Double_t A2,Double_t phi,TString u,Double_t p)
{
 
 fI=0;
 fQ=0;
 fU=0;
 fV=0;
 
 if (A1<0 || A2<0 || A1*A2==0 || p<=0)
 {
  cout << " *NcStokes::SetJonesVector* Inconsistent input." << endl;
  cout << " A1:" << A1 << " A2:" << A2 << " phi:" << phi << " " << u << "." << " p:" << p << endl;
  return;
 }
 
 Double_t pi=acos(-1.);
 
 if (u=="deg") phi*=pi/180.;
 
 fI=(A1*A1+A2*A2)/p;
 fQ=A1*A1-A2*A2;
 fU=2.*A1*A2*cos(phi);
 fV=2.*A1*A2*sin(phi);
}

Double_t NcStokes::GetParameter(TString name,TString u)
{
 
 Double_t value=0;
 
 if (fI<=0)
 {
  cout << endl;
  cout << " *NcStokes::GetParameter* Inconsistent data encountered : I=" << fI << endl;
  cout << " --- The Stokes vector (I,Q,U,V) is also known as (S0,S1,S2,S3)." << endl;
  return 0;
 }
 
 Double_t pi=acos(-1.);
 
 Double_t P=sqrt(fQ*fQ+fU*fU+fV*fV);
 Double_t L=sqrt(fQ*fQ+fU*fU);
 Double_t a=sqrt(0.5*(P+L));
 Double_t b=sqrt(0.5*(P-L));
 Double_t A1=sqrt(0.5*(P+fQ));
 Double_t A2=sqrt(0.5*(P-fQ));
 
 if (name=="I" || name=="S0") value=fI;
 if (name=="Q" || name=="S1") value=fQ;
 if (name=="U" || name=="S2") value=fU;
 if (name=="V" || name=="S3") value=fV;
 if (name=="P") value=P;
 if (name=="L") value=L;
 if (name=="C") value=fabs(fV);
 if (name=="a") value=a;
 if (name=="b") value=b;
 if (name=="e" && P) value=sqrt(1.-(b*b)/(a*a));
 if (name=="A1") value=A1;
 if (name=="A2") value=A2;
 if (name=="theta" && L)
 {
  value=0.5*atan2(fU,fQ);
  if (u=="deg") value*=180./pi;
 }
 if (name=="beta" && P)
 {
  value=atan2(b,a);
  if (u=="deg") value*=180./pi;
 }
 if (name=="helicity" && fV)
 {
  value=1;
  if (fV<0) value=-1;
 }
 if (name=="phi" && (fV || fU))
 {
  value=atan2(fV,fU);
  if (u=="deg") value*=180./pi;
 }
 
 return value;
}

void NcStokes::Data(TString u)
{
 
 if (fI<=0)
 {
  cout << endl;
  cout << " *NcStokes::Data* Inconsistent data encountered : I=" << fI << endl;
  cout << " --- The Stokes vector (I,Q,U,V) is also known as (S0,S1,S2,S3)." << endl;
  return;
 }
 
 Double_t P=GetParameter("P");
 Double_t L=GetParameter("L");
 Int_t h=TMath::Nint(GetParameter("helicity"));
 Double_t A1=GetParameter("A1");
 Double_t A2=GetParameter("A2");
 Double_t phi=GetParameter("phi",u);
 Double_t a=GetParameter("a");
 Double_t b=GetParameter("b");
 Double_t e=GetParameter("e");
 Double_t beta=GetParameter("beta",u);
 Double_t theta=GetParameter("theta",u);
 
 cout << " *NcStokes::Data* Listing of all polarisation information." << endl;
 cout << " --- The Stokes vector (I,Q,U,V) is also known as (S0,S1,S2,S3)." << endl;
 cout << " Stokes parameters....................: I=" << fI << " Q=" << fQ << " U=" << fU << " V=" << fV << endl;
 cout << " Total beam intensity.................: I=" << fI << endl;
 cout << " Total polarisation intensity.........: P=" << P << endl;
 cout << " Linear polarisation intensity........: L=" << L << endl;
 cout << " Circular polarisation intensity......: C=" << fabs(fV) << endl;
 cout << " Fractional polarisation intensities..: P/I=" << P/fI << " L/I=" << L/fI << " C/I=" << fabs(fV/fI) << endl;
 if (P)
 {
  cout << " Jones (x,y) field vector (E1,E2).....: |E1|=" << A1 << " |E2|=" << A2 << " (phi1-phi2)=" << phi << " " << u << "." << endl;
  cout << " Polarisation ellipse (semi axes a,b) : a=" << a << " b=" << b << " eccentricity=" << e << " arctan(b/a)=" << beta << " " << u << "." << endl;
  if (L) cout << " Ellipse orientation angle............: " << theta << " " << u << "." << endl;
  if (fV) cout << " Polarisation helicity................: " << h << endl;
 }
}