[GRASSLIST:4986] Re: US Census boundary file problem

Radim Blazek blazek at itc.it
Mon Nov 18 04:56:03 EST 2002


On Monday 18 November 2002 12:17 am, Michel Wurtz wrote:
> Michael Ash wrote:
> > I have downloaded boundary files from the U.S. Bureau of the
> > Census (http://www.census.gov/geo/www/cob/) in .e00 format.
> > For example st99_d00.e00 is the complete state boundaries
> > for the U.S. for 2000.  When I import the file with
> > m.in.e00, d.vect shows a map of the United States but the
> > raster file produced by v.to.rast has holes, specifically
> > Texas and Massachusetts.
> >
> > Perhaps the vector areas are not closed for those states?
> >
> > How is it possible in GRASS to close the vector areas if
> > that is indeed the problem?
>
> use v.digit.  But it may also be the lack of a label point
> inside the polygon (verify wether v.support shows errors or not
> when running on your vector file).  This can also be corrected with
> v.digit.

Try to click on that areas with d.what.vect, you can get:
1) no area -> unclosed areas
2) area not labeled -> missing category
3) labeled area -> strange

Are you sure that attributes imported from e00 were integers > 0?
As cats < 1 are not valid, such records are deleted from dig_att
by v.support. 

Radim




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