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Viewing changes to src/legacy/Optics/TransferMap.cc

  • Committer: Durga Rajaram
  • Date: 2013-11-19 02:09:06 UTC
  • mfrom: (659.1.77 rc)
  • Revision ID: durga@fnal.gov-20131119020906-t2vxx4h2yr0f09tj
Tags: MAUS-v0.7.4
MAUS-v0.7.4

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src/legacy/Optics/TransferMap.cc
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double TransferMap::PhaseAdvance(int axis) const
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{
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        CLHEP::HepMatrix subMatrix = GetFirstOrderMap().sub(axis*2+1, axis*2+2, axis*2+1, axis*2+2);
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        double    phaseAdvance = acos( (subMatrix[0][0] + subMatrix[1][1])/2. ) ;
 
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  // TM given by
 
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  // cos(\phi) + \alpha sin(\phi), \beta sin(\phi) / p
 
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  // - \gamma sin(\phi),            cos(\phi) - \alpha sin(\phi)
 
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  // we can get the phase advance quadrant by considering both sin(phi) and
 
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  // cos(phi) and using atan2(phi)
 
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  double n00 = (subMatrix[0][0]-subMatrix[1][1])/2.; // alpha sin(phi)
 
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  double sin_phi = sqrt(-n00*n00 - subMatrix[0][1]*subMatrix[1][0]); // ((-alpha^2 + beta gamma) sin^2(phi) )^0.5
 
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  double cos_phi = (subMatrix[0][0] + subMatrix[1][1])/2.; // cos(phi)
 
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        double phaseAdvance = atan2(sin_phi, cos_phi);
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        if(phaseAdvance != phaseAdvance) throw(Squeal(Squeal::recoverable, "Complex phase advance", "TransferMap::PhaseAdvance")); 
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        return    phaseAdvance;
 
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        return phaseAdvance;
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}
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MAUS::PolynomialMap* TransferMap::GetPolynomialMap() {