[G8b_run] Photon Corrections (taggerSag)

[Charles Hanretty]

Hello all,
      Below is the C++ translation from the Fortran code that Mike wrote to 
correct the photon energies.

   float E0 = 4.55;
   double egdivE0;
   egdivE0 = pho_energy/E0 + 0.00134;

   if (egdivE0 < 0.401) {
     egdivE0 = egdivE0 - 0.00599597 + 0.0390912*egdivE0 -
0.0573218*egdivE0*egdivE0;
   }
   if ((egdivE0 >= 0.401) && (egdivE0 <= 0.674)) {
          egdivE0 = egdivE0 - 0.0181293 + 0.0675599*egdivE0 - 
0.0541268*egdivE0*egdivE0;
   }
   if (egdivE0 > 0.674) {
          egdivE0 = egdivE0 - 0.0511162 + 0.138208*egdivE0 - 
0.0867757*egdivE0*egdivE0;
   }

   pho_energy = egdivE0*E0 + pho_energy*(-0.0035);

Where "pho_energy" is the energy of the photon as taken from the data 
file and "E0" is the (e-)beam energy.

    A CLAS-note for the g8b Tagger Sag study is almost finished.

-Chuck