Plan position indicator designing using qt

[seok]

Hi,
i am trying to design plot/graph which plot the radians and degrees in a 360 circle
i almost got what i was looking for, by using QPolarchart everything is correct but since polarchart does not allow rectangle zooming which is very much required in my case (i need to zoom in on the particular plotted points)

so now how do i get the selection/rectangular zooming in polarchart ( i dont know if this is possible)
what are my other options
i basically need a circle with degrees marked on it and my points needs to get plotted inside that circle according to the radian and degree values

if any one has any suggestions please share them thank you