[GRASSLIST:4226] Re: Generating new linked attribute table after v.overlay

[Radim Blazek]

Reclass first input vectors by state ID (v.reclass col=STATE),
then run v.overlay and the table linked to field 1 contains
what you want.

Radim

On Saturday 21 August 2004 00:54, Craig Aumann wrote:
> I'm working in 5.7.
>
> Suppose we have two polygons which have attributes linked to an
> associated PostGRESQL database.
>
> i.e.
>
> ----------------
>
> |   1   |  2    |
>
> -----------------
>
> linking off to a table:
>
> LINK_KEY   STATE
> 1           57
> 2           59
>
>
> I now overlay  another polygon:
> ----------------
>
> |   10  |  11   |
>
> *******************
>
> |   12  |  13   |
>
> ******************
>
> |   14  |  15   |
>
> -----------------
>
> and what I want to do is end up with an associated table linked to the
> result of the overlay that looks like this:
>
> LINK_KEY  STATE NEW_STATE
> 10          57       57
> 11          59       59
> 12          57      157
> 13          59      159
> 14          57       57
> 15          59       59
>
> I need a few kicks in the right direction (alright, I need to have my
> hand held in a major way!) to figure out how to proceed following
> v.overlay to  ensure that each new polygon resulting from the overlay
> has one (and only one!) unique link_key into the new attribute table AND
> also how to do the associated query processing based on the STATE (and
> other columns) of the original polygons (stored in their original linked
> table above) which the overlaid polygon intersects.
>
>
> Thanks!
> Craig