[GRASS-user] Perpendicular projection of points onto line

[Carlos Grohmann]

Oops,  of course that the shortest distance will be perpendicular. I should do one thing at a time... trying to code while in a field trip in the Amazon is not the best idea... 

-- 
Carlos Grohmann
Sent with Sparrow (http://www.sparrowmailapp.com/?sig)


On Thursday, 10 de May de 2012 at 17:28, Carlos Grohmann wrote:

> Thanks Micha. I though of v.distance but I wasn't sure if the connectors would be perpendicular  
> 
> -- 
> Carlos Grohmann
> Sent with Sparrow (http://www.sparrowmailapp.com/?sig)
> 
> 
> On Thursday, 10 de May de 2012 at 14:42, Micha Silver wrote:
> 
> > On 05/10/2012 06:31 PM, Carlos Grohmann wrote: 
> > > Hi all 
> > > I'm thinking if  there is a way to project a series of points into a line, but this projection must be in a direction perpendicular to the line.
> > > 
> > One approach is a three step process: 
> > 1- Begin with v.distance from your points to the line. The 'output' parameter will be a line vector of the (perpendicular) connectors from the points to the line.
> > 2- Next do v.patch to merge the connectors to the line.
> > 3- And finally v.clean with tool=break error=connector_points.  The 'error' parameter contains all those points where a new intersection had to be created after patching the connectors to the line vector. 
> > 
> > (There is a chance that one connector will intersect the line exactly on a node, and then v.clean won't find that point since it's not an 'error'. But that's probably a very rare case.)
> > 
> > HTH,
> > Micha
> > > Tks 
> > > 
> > > -- 
> > > Carlos Grohmann
> > > Sent with Sparrow (http://www.sparrowmailapp.com/?sig) 
> > > 
> > > 
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> > > 
> > > 
> > > _______________________________________________ grass-user mailing list grass-user at lists.osgeo.org (mailto:grass-user at lists.osgeo.org) http://lists.osgeo.org/mailman/listinfo/grass-user This mail was received via Mail-SeCure System. 
> > 
> > 
> > -- Micha Silver GIS Consultant, Arava Development Co. http://www.surfaces.co.il 
> 

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