I have done that in defining reg1 and reg2;
For example, reg1 corresponds to rectangular region bounded by 80-85 E and 22-25 N
you can define such rectangular boxes for each of your rectangula subregions.
However, if your region has irregular shape (i.e. can't be divided into rectangular boxes) then you need a shape file (or coordinate of the boundary) from which you can creat a NetCDF file and then use pt_in_poly function if ferret to creat the mask
Jagadish
On Monday, May 19, 2014 10:42 AM, Nitin Patil
<nitinpatil85@xxxxxxxxx> wrote:
thanks for your quick reply but where to specify my irregular shape lat lon notation which i have to extract..