Message-ID: <C9D4CB93-8403-4A81-AC88-C3EEF8D0946C@comcast.net>
Date: 2013-06-16T16:53:41Z
From: David Winsemius
Subject: trying to fit a thin plate spline to a triangular plot
In-Reply-To: <2F26AF2C2FA31A43AEEDD56E1492C19D19240920@VMEXCHANGEMBS3A.isad.isadroot.ex.ac.uk>
On Jun 16, 2013, at 7:39 AM, Rapkin, James wrote:
> Hi
>
> Has anyone tried to fit a thin plate spine to a triangular plot before? I'm having trouble working out a piece of code to make it possible with three axes.
Only two axes in a triangular plot are independent.
> I have done it before with two axes.
>
> I've found a package I prefer that makes triangular plots (plotrix) using the triax.plot() function. An example of some data and the plot follows:
>
> graph.data<-data.frame(a=c(9,6.2, 5.9,8.1,8.9,56.9,50,39.5,62.1,49.9,4.2,3,6,4.1),
> b=c(1.8,1.2,1.2,1.6,1.8,11.4,10,7.9,12.4,10,4.2,3,6,4.1),
> c=c(1.8,1.2,1.2,1.6,1.8,11.4,10,7.9,12.4,10,4.2,3,6,4.1),
> d=c(10,15,16,14,13,18,19,17,20,19,21,22,22,23))
>
> triax.plot(graph.data, main="Title", no.add=F, show.grid=T,tick.labels=list(l=seq(10,90,by=10),r=seq(10,90,by=10),b=seq(10,90,by=10)),
> pch=1,cc.axes=TRUE)
>
> I want to fit the 'd' data as a spline to the plot.
Looking at the data I am unable to imagine how that could meaningfully support a 2d spline fit.
>
> Any help is greatly appreciated.
This was cross-posted to StackOverflow and R-help. SO does not have a policy against cross-posting, but Rhelp does.
--
David Winsemius
Alameda, CA, USA