[Qgis-user] Interpolation Plugin

[ALT SHN]

Thanks a lot Marco!

It's all much more clear to me now - specially after consulting your
dissertation - it has a lot of valuable information for me. Very helpful
share - thanks!

Paolo: I've followed your sugestion and opened a tickect suggesting a better
documentation for the interpolation plugin -->
https://trac.osgeo.org/qgis/ticket/3103

Best regards

2010/10/10 Marco Hugentobler <marco.hugentobler at sourcepole.ch>

> Hi André
>
> > Now my question is: what does it mean the options "structured lines" and
> > "break lines"?
>
> These options have no influence for IDW interpolation, only for TIN
> interpolation.
>
> -structure lines: triangle edges are constrained to line / polygon features
> (e.g. to prevent triangle edges crossing valleys, ridges or contours)
>
> -breaklines: like structure lines. But for cubic triangle interpolation (
> clough-tocher), the break line is a edge (so not continuously
> differentiable)
> (details in
>
> http://www.geo.uzh.ch/fileadmin/files/content/abteilungen/gis/research/phd_theses/thesis_MarcoHugentobler_2004.pdf
> ,
> chapter 5)
>
> >And by the way,
> > what does the "Distance coefficient" implies?
>
> It's the same parameter as the 'power' (IDW only has one parameter).
>
>
> Regards,
> Marco
>
> Am Samstag, 9. Oktober 2010, um 19.48:23 schrieb ALT SHN:
> > Hello List,
> >
> > I have a question about the QGIS Interpolartion Plugin.
> >
> > I have a line vector representing altitude by means of isolines of 10m,
> > covering an area of about 400 square km. I have read scientif paper that
> > advices the use of IDW with power 1-3 for hilly topography (thats my
> case).
> >
> > Now my question is: what does it mean the options "structured lines" and
> > "break lines"? How can they affect the accuracy of my DEM? And by the
> way,
> > what does the "Distance coefficient" implies?
> >
> > Thanks in advance
> >
> > André
>
>
> --
> Dr. Marco Hugentobler
> Sourcepole - Linux & Open Source Solutions
> Webereistr. 66, CH-8134 Adliswil, Switzerland
> marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
> Technical Advisor QGIS Project Steering Committee
> _______________________________________________
> Qgis-user mailing list
> Qgis-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-user
>



-- 
---------------------------------------------------------------
Associação Leonel Trindade
SOCIEDADE DE HISTÓRIA NATURAL

Apartado 25 2564-909 Torres Vedras Portugal
Sede e Biblioteca: rua Cavaleiros da Espora Dourada, 27A 2560 Torres Vedras

Laboratório de Paleontologia e Paleoecologia: Polígono Industrial do Alto do
Ameal 2565-641 Ramalhal
http://alt-shn.blogspot.com
www.alt-shn.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20101010/75c522df/attachment.html>