[GRASS-user] Area/poly from lines

Michael Barton michael.barton at asu.edu
Sun Feb 26 14:37:58 EST 2012

Why do you want to add "width" to these? 

A GIS is not like a drawing or CAD program. There is no width to a vector line--including shapefiles. These lines do have geometry. As vector primitives (i.e., lines in the GIS), they are the connections between nodes. In GRASS, they also have topology (shapefiles have minimal topology). What 3D program is having trouble reading your data?

For display and export to a graphic program, you can set the displayed line width in the vector layer properties. 

You can create parallel lines a given distance apart with v.parallel. But that may not be helpful.


On Feb 26, 2012, at 10:00 AM, <grass-user-request at lists.osgeo.org> wrote:

> Date: Sat, 25 Feb 2012 15:13:28 -0200
> From: Daniel Victoria <daniel.victoria at gmail.com>
> Subject: Re: [GRASS-user] Area/poly from lines
> To: Moritz Lennert <mlennert at club.worldonline.be>
> Cc: giannis Nj <netsagief at hotmail.com>, grass-user at lists.osgeo.org
> Message-ID:
> 	<CA+irsJi_yS-LYVjyFuPFhhTQWjKGuQBuv=0Exqr84H_w6j1eRA at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
> Maybe create a buffer around the lines?
> 2012/2/21 Moritz Lennert <mlennert at club.worldonline.be>:
>> On 21/02/12 11:46, giannis Nj wrote:
>>> I have a shapefile with lines only. Is it possible to add some area to
>>> these lines? Like fatening the lines. The lines are the walls of a
>>> castle but I can't use their exports ("file without geometry" gives as
>>> an error some 3d programs), so I want to add some width to these lines.
>>> Maybe adding polygons will help me too?
>> One possible strategy might be to transform the lines to raster, thicken
>> them and the retransform to vector as areas:
>> v.to.rast
>> r.grow
>> r.to.vect feature=area
>> Moritz
>> _______________________________________________
>> grass-user mailing list
>> grass-user at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/grass-user

C. Michael Barton
Visiting Scientist, Integrated Science Program
National Center for Atmospheric Research &
University Consortium for Atmospheric Research
303-497-2889 (voice)

Director, Center for Social Dynamics & Complexity 
Professor of Anthropology, School of Human Evolution & Social Change
Arizona State University
www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu

More information about the grass-user mailing list