[GRASSLIST:4226] Re: Generating new linked attribute table after v.overlay
Radim Blazek
blazek at itc.it
Mon Aug 23 05:57:00 EDT 2004
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
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