[GRASS-user] using v.line.center

Maciej Sieczka tutey at o2.pl
Thu Jun 5 13:38:55 EDT 2008

Manuel Sangiao pisze:

> WARNING: Cannot get point on line: cat=927 offset=89379.795093 (line 
> lenght=2.219076) P 927 927 89379.795093
> I guess the reason for this error is the projection (mapset?) unit.
> The projection unit(s) in my mapset is degree(s). And the length
> units are meters.

v.line.center as it is can't work in latlon Location. It uses v.to.db
for length calculation, which cannot measure in degrees, and then pipes
the result to v.segment, which assumes Location unit - if it's degree
the script won't work.

It would be cool if v.segment could accept offsets in various units.

I should fix v.line.center to check location units, and update the
manual. Someday.

> So, how can i change the mapset units. Should I create another mapset
> with the properly units?

Reproject the data into a metric location.

Maciej Sieczka

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