From: Larry Layne <ljlayne_at_unm.edu>

Date: Thu 26 Oct 2006 - 16:50:11 GMT

}

z <- runif(100)

reggrid <- data.frame(u,v,z)

is.data.frame(reggrid)

wireframe(z~u*v,reggrid,scales=list(arrows=FALSE),drape=TRUE,colorkey=TRUE)

** #LINEAR INTERPOLATION
**

reggrid <- interp(u,v,z,linear=TRUE,extrap=FALSE)** #WIREFRAME SURFACE PLOT FROM INTERPOLATED DATA
**
wireframe(reggrid$z,scales=list(arrows=FALSE),drape=TRUE,colorkey=TRUE)
** #PLOT IMAGE, CONTOUR, AND POINTS
**

plot(u,v)

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Fri Oct 27 03:12:06 2006

Date: Thu 26 Oct 2006 - 16:50:11 GMT

--On Wednesday, October 25, 2006 4:46 PM -0700 Deepayan Sarkar <deepayan.sarkar@gmail.com> wrote:

> On 10/25/06, Larry Layne <ljlayne@unm.edu> wrote:

*>> Per the message from Alexander Nervedi, 29 April 2006:
**>>
**>> > I have to be making a riddiculously silly ommission.
**>> > when I run the fillowing i get the cloud plot ok. But I cant figure
**>> > out what I am missing out when I call wireframe.
**>>
**>> > Any help would be appreciated.
**>>
**>> > x<-runif(100)
**>> > y<-rnorm(100)
**>> > z<-runif(100)
**>>
**>> > temp <-data.frame(x,y,z)
**>> > wireframe(x~y*z,temp)
**>> > cloud(x~y*z,temp)
**>>
**>> There is something funny about the way wireframe treats a data frame
**>> object created using "data.frame" vs. using "expand.grid". For instance,
**>> this works:
**>
**> There's nothing funny about it, ?wireframe clearly says:
**>
**> In the case of 'wireframe',
**> calculations are based on the assumption that the 'x' and 'y'
**> values are evaluated on a rectangular grid defined by their
**> unique values.
*

Sorry about incorrectly interpreting this part of the description about wireframe.

> In the original example, the (x, y) values are clearly not on a grid,

*> and in your (very strange) example below, they are not on a
**> rectangular grid, as can be seen using
**>
**> xyplot(u ~ v, reggrid)
*

One of the nice things about posting questions in a list is that it is so conveniently easy to embarrass oneself in public. The corrected code follows and works just fine:

library(lattice)

**###MAKE-BELIEVE DATA
**

u <- mat.or.vec(100,1)

v <- mat.or.vec(100,1)

ij=0

for(i in 1:10)

{

for(j in 1:10)

{ ij=ij+1 u[ij]=i v[ij]=j }

}

z <- runif(100)

reggrid <- data.frame(u,v,z)

is.data.frame(reggrid)

wireframe(z~u*v,reggrid,scales=list(arrows=FALSE),drape=TRUE,colorkey=TRUE)

>> In addition, I would also like to

*>> do what Alexander is trying to do, which is create a wireframe from
**>> irregular lattice data.
*

Although what I would really like to do is plot a 3D Triangulated Irregular Network (TIN) surface of the irregularly spaced points, the following sort of gets me there in the short-term:

**##INTERPOLATE USING AKIMA PACKAGE AND PLOT SURFACES
**
library(akima)

library(lattice)

** #MAKE-BELIEVE DATA
**

u <- runif(30) v <- runif(30) z <- runif(30)

reggrid <- interp(u,v,z,linear=TRUE,extrap=FALSE)

plot(u,v)

image (reggrid,add=TRUE) contour(reggrid,add=TRUE) points (u,v,pch = 3)

Larry Layne

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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Fri Oct 27 03:12:06 2006

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