The design and implementation of MdcPatRec tracking algorithm for the BES III main drift chamber

The tracking algorithm for the BES Ⅲ Main Drift Chamber,MdcPatRec,is implemented using object-oriented techniques and C++ language.The tracking algorithm is used to find the charged particle's track in the drift chamber and to reconstruct its momentum and position.After description of implementation details,physics and system performances are presented with Monte Carlo simulated data.