added argument to make MapView inverse able to reconstitute forward mapping
added argument to make MapView inverse able to reconstitute forward mapping

cjlee112/pygr,RitwikGupta/pygr,theoryno3/pygr,cjlee112/pygr,theoryno3/pygr,RitwikGupta/pygr,GenDataPro/pygr,GenDataPro/pygr,cjlee112/pygr,GenDataPro/pygr,RitwikGupta/pygr,theoryno3/pygr,cjlee112/pygr