Transform

Hi , I have a polygon (METAL1) in an instance. Im using dbTransform to get the xy of the polygon w.r.t toplevel, but im not able to. For rectangles it is working fine but for polygons it is not giving the exact xy. exact xy = 15.9:1.36 with transform = (17.533 4.965) Inputs are ((db:54977564 cellView db:63255596 objType "inst" prop nil bBox ((16.388 4.46) (20.275 8.92) ) children nil groupMembers nil isAnyInst t isShape nil matchPoints nil net nil parent nil physConns nil pin nil purpose "cell" textDisplays nil assocTextDisplays nil baseName "I1" cellName "XOR" instHeader db:63559468 instTerms nil libName "test_lib" master db:64806956 name "I1" numInst 1 viewName "layout" conns nil mag 1.0 orient "R0" status "firm" transform ((16.855 4.76) "R0" 1.0) xy (16.855 4.76) ) (db:64837364 cellView db:64806956 objType "polygon" prop nil bBox ((1.145 0.505) (1.415 3.4) ) children nil groupMembers nil isAnyInst nil isShape t matchPoints nil net nil parent nil physConns nil pin nil purpose "drawing" textDisplays nil assocTextDisplays nil layerName "ME1" layerNum 46 lpp ("ME1" "drawing") nPoints 12 points ((1.415 1.21) (1.335 1.21) (1.335 1.87) (1.415 1.87) (1.415 3.16) (1.295 3.16) (1.295 3.4) (1.145 3.4) (1.145 0.505) (1.295 0.505) (1.295 0.76) (1.415 0.76) ) ) ) Please let me know why im getting an error for polygons.