From renaud.lancelot at gmail.com  Mon Oct  3 18:29:57 2005
From: renaud.lancelot at gmail.com (Renaud Lancelot)
Date: Mon, 3 Oct 2005 18:29:57 +0200
Subject: [Rd] interpolation using akima (PR#8174)
In-Reply-To: <20051003161316.35D4A1DA5C@slim.kubism.ku.dk>
References: <20051003161316.35D4A1DA5C@slim.kubism.ku.dk>
Message-ID: <c2ee568005100309296238eb58@mail.gmail.com>

This message should be sent to the package maintainer, not to this list.

Moreover, it works fine with my installation (i.e., I don't get the
bug you describe):

R:

platform i386-pc-mingw32
arch     i386
os       mingw32
system   i386, mingw32
status   beta
major    2
minor    2.0
year     2005
month    09
day      24
svn rev  35666
language R


akima:
Package:       akima
Version:       0.4-5
Date:          2005-07-21

Best,

Renaud


2005/10/3, jonathan_lees at unc.edu <jonathan_lees at unc.edu>:
> Full_Name: Jonathan Lees
> Version: 2.0.1
> OS: linux-gnu
> Submission from: (NULL) (152.2.75.65)
>
>
> there is a problem with calculating the convex hull in 2-D interpolation using
> the codes interp fromt eh akima package:
>
> x =c(0.6505304, -1.1821562, -0.2600792,  0.7913716)
> y = c(1.0424226,  0.1754048, -1.4523334,  0.2349112)
> z =  c(0.000, 3.042, 0.370, 0.122)
>
>
>    EX = seq(from=min(x), to=max(x), length=100)
>     WHY = seq(from=min(y), to=max(y), length=100)
>
>  ZZ = interp(x=x, y=y, z=z, xo=EX, yo=WHY, extrap=FALSE)
>
> plot(x,y, type='n')
> image(ZZ, add=TRUE)
> points(x,y)
> text(x,y,labels=z)
>
> BUG:
> Notice the convex hull is wrong.
> It includes only 3 of the 4 points provided.
> If you add another point near by it does some
> really wierd stuff.
> x = c(x,  -0.3950865)
> y = c(y,  -1.449117)
> z = c(z, .37)
>
>
>
> I do not think it should behave in this manner.
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>


--
Renaud LANCELOT
Directeur Adjoint charg? des Affaires Scientifiques
Deputy Director for Scientific Affairs

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[Rd] interpolation using akima (PR#8174)
Renaud Lancelot