Goal : predict BSMD-P relative gain corrections for every eta bin 

Method : find average slope per eta slice, fit gauss, determine average slope : avrSlope(iEta)

Gain correction formula is used only for extreme deviations:  

• gainCorr_i = slope_i/avrSlope(iEta),  i =1,..,18,000
• if( fabs(1-gainCorr)<0.10) gainCor=1.0  // do not correct

Fig 1 Example of 2 eta slices

Fig 2 LEFT: Slope distribution vs. eta-bin, average marked by crosses

RIGHT: predicted gain correction. Correction=1 for strips w/ undetermined gains. 

Fig 3 Predicted gain correction. Correction=1 for ~14K of 18K strips.

Fig 4 The same predicted gain correction vs. stripID.