Two questions. Is there a way to retrieve or calculate the bin number for a particular angle of theta or phi without going through the cell functions. Also, what are the definitions for the particular arguments sent to the following cell function. int constructID(int thetabin, int phibin, int layer, int ec, int sys) I know the meanings of thetabin phibin and layer, but what about ec (endcap?) and sys (system number?). What I need to do is map a particular coordinate that lies just outside the EMC to a cell on the first layer. -Brandon Drummond