8.4.13 addPoly(self,channel=0,phase=1,poly=[10.,0.,10.,10.]):

addPoly $<$ DataAna(BoaDataEntity.DataEntity): $<$ BoaDataAnalyser.py

    NAM: addPoly (method)  
    DES: add polynomial baseline
    INP: 
         (int)      channel  =  channel. for -1 all channels. first channel=0
         (int)      phase    =  phase to be used. For -1 all. else: 0,1,2
         (int)      poly     =  polynomial coefficients, relative to
                                current mean and rms