[GRASS5] points in interior or inside shape

[Michael Ash]

I want to assign each of a set of points (now a site layer) to the 
geographic area (Census tract) in which it resides.

I have a vector layer converted with m.in.e00 and v.support from a .e00 
U.S. Census cartographic boundary file.  So I think that the unit of 
observation is the polygon.

I have a site layer.

Both layers are in the same region, projection, etc.  If I display both, 
I can see the sites overlaid on the shapes.

How do I establish "interiority"?  That is, I think that I would like to 
generate a new site layer that assign to each site the identifier of the 
polygon it is inside.

I would welcome any advice that you can offer.  I have considered 
converting the vector layer to raster and using s.sample or converting 
both to raster and using r.mapcalc.  Is there a better approach?

Best regards,

Michael Ash
Assistant Professor of Economics
and Public Policy
UMass-Amherst
mash at econs.umass.edu