[GRASS-user] Two questions

[Markus Neteler]

On Sat, May 17, 2008 at 2:09 AM, Richard Chirgwin
<rchirgwin at ozemail.com.au> wrote:
> Hi,
>
> 1) I have installed Grass-6.3 (compiled from source to work on Ubuntu /
> Freespire). The new installation can't see the mysql driver (although 6.2
> still sees it). How do I tell Grass-6.3 where the driver is?

Please use the
  --with-mysql            support MySQL functionality (default: no)
  --with-mysql-includes=DIRS
  --with-mysql-libs=DIRS  MySQL library files are in DIRS
switches. The file "config.log" contains the indication of the problem.

> 2) More complex, a question about polygons. I have maps with large numbers
> of polygons with shared boundaries. Is there any way to count the number of
> boundaries one polygon shares with its neighbors?

You need to use two vector layers (v.category) and v.to.db. See its manual
page for an example (or, in the new GRASS book, see
"6.5.9 Length of common polygon boundaries"  for a similar task).

Markus