MySQL and Grass

Terry Duell terry.duell at
Wed Nov 10 22:51:57 EST 1999

Robb Hill wrote:

> Hi,
> I have a bunch (500k) of line segments(related to a 'polygon' table) and
> around 70k points, both in a MySQL database.  I need to do a
> point-in-polygon query. i.e. I want to know which polygons contain each
> of the 70k points.

I have been looking at the GRASS Programmer's Manual, and the Vector
Library does include routines which might be helpful for this task, but
they then need to be called within appropriate code. Some GRASS programmers
out there may be able to offer more useful advice as to whether what you
need has already been done or can in fact be done.
The routines I refer to are:
dig_point_in_area (Map,x,y,pa)  is point in area?
dig_point_to_area (Map,x,y)     find which area point is in

This doesn't actually solve your problem, but it may help you get there :-)


>   --
> Terry Duell, Senior Mobility Engineer
> Army Engineering Agency
> Maribyrnong, Victoria, Australia
> ph:61-3-93195837 fax:61-3-93195830

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