[GRASS-user] Smoothing unclosed contour

Markus Metz markus.metz.giswork at googlemail.com
Wed Oct 26 04:12:58 EDT 2011

Dmitriy Tyugaev wrote:
> Hi list,
> Help me please! I have a set of unclosed contours, which are created from
> raster cropped by the mask.
> After smoothing with "v.generalize method=boyle look_ahead=5" I have
> obtained smooth, but duplicated contours.
> http://www.image-share.com/ipng-1014-170.html
> http://www.image-share.com/ipng-1014-171.html
> How can I fix it?

That looks like duplicate contours, something could have gone wrong
when extracting contour lines. You can try to clean the contours first
by breaking lines at intersections, then removing duplicates and
finally building polylines. Then try to smooth them again.

v.clean tool=break,rmdupl type=line
v.build.polylines cats=first


Markus M

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