Average within a circle

[M. Mahakur]

Respected GrADS Users,

I have gridded data along with UNDEF values at certain grid locations. I
wants to find the 'ave' (if possible 'aave') of a certain parameter
available within a circle of radius (say 2 degree), and I wants to loop
this in time. I will specify the centre of circle at various TDEF's. The
centre of the circle during most of the times does not coincide  with
any grid point.

Can anybody kindly provide me the script or some hints.

Thanking you.

With Best Regards,

M. Mahakur