[R-sig-Geo] Local plane fitting to Point Cloud

[Edzer Pebesma]

Ludwig, your email does not contain the original posting, please include
or repeat in future mailings.

The original question was, I believe, about local fitting of trend surfaces.

This error can for instance happen when your neighbourhood is too small,
or does not contain enough information.

For a first order linear trend surface, a local neighbourhood should
have at least three points, and irrespective the neighbourhood size, the
points should not be aligned (on a straight line). My hint is that one
of these conditions is not met in your setup.

You can try to set debug level to powers of two (2, 8 or 16 seem
relevant) to get detailed input about the conditions under which this
happens.

On 06/10/2013 05:15 PM, Ludwig Hilger wrote:
> Hello everybody,
> 
> unfortunately I have to come up with a follow-up question. As described
> above, this has worked now perfecty at first with some of my data, but with
> another dataset (but it has the same structure, etc) I get the following
> error:
> 
> "solve.c", line 88: singular matrix in function Usolve()
> Fehler in predict.gstat(g, newdata = newdata, block = block, nsim = nsim, :
>  Usolve
> 
> I have no idea what my R is trying to tell me... any hints?
> 
> thank you again everybody,
> 
> Ludwig
> 
> 
> 
> -----
> Dipl. Geogr. Ludwig Hilger
> Wiss. MA
> Lehrstuhl für Physische Geographie
> Katholische Universität Eichstätt-Ingolstadt
> Ostenstraße 18
> 85072 Eichstätt
> 
> Tel.: 08421-93-1180 
> --
> View this message in context: http://r-sig-geo.2731867.n2.nabble.com/Local-plane-fitting-to-Point-Cloud-tp7583724p7583746.html
> Sent from the R-sig-geo mailing list archive at Nabble.com.
> 
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-- 
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
83 33081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de