Update sandbox pv.cpp file
Update sandbox pv.cpp file

git-svn-id: http://svn.code.sf.net/p/petavision/code/sandbox@4890 7c0444ca-5550-0410-9008-faecdbe78eb5

Former-commit-id: 92ed7c1510b2abd2f42bb77ad104408f59dfbbed
PetaVision/OpenPV,PetaVision/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV