Hi Sarith,
Thanks for your reply. 
I understand that DGP metric works on the basis of image based simulations. But I was talking about DGPs (simplified DGP) where only the vertical illuminance is required and the metric can be derived using a formula for simplified DGP.
I read your post on the same here.
Wouldn’t it be important to define the vector of the analysis point? I saw a few example files where some users have done a simplified DGP calculation for their project where they have directly input the illuminance output of the three-phase simulation into a formula to derive the simplified DGP (where the analysis grid point vectors act like as mentioned in your earlier reply)