similar to: "Local trend surfaces" Ex from V&R MASS

R- Users: Can someone indicate what I am during wrong? This is a script essentially from Venerable & Ripley's text on interpolating a surface with loess function but I can not get it to run. Thanks. John Lewis Professor McGill University Montreal library(MASS) library(modreg) data(topo) par(mfcol=c(2,2), pty="s") topo.loess <- loess(z ~ x * y, topo, degree=2,

I'm reading Ripley-Venables "Modern Applied Statistics with S - Fourth edition" , at the same time trying the examples proposed in the book using R 1.8.1 under linux. Now I'm trying the following code from the book (example code of spatial statistics at page 76) with R : | data(topo) library("spatial") topo.loess<-loess(z ~ x * y, topo, | degree= 2,span=0.25) |

Hi, I was wondering if anyone knows of a way by which one can estimate values from a contour plot created by using the loess function? I am hoping to use the loess contour plot as a means of interpolation to identify the loess created values at points at pre-defined (x,y) locations. Could anyone point me in the right direction please? Thanks. Laura Quinn Institute of Atmospheric Science School

If a run a LOESS model and then produce a smoothed surface: Is there any way to determine the coordinates of the local maxima on the surface? [[alternative HTML version deleted]]

Dear All, I was looking for the color index in?image function,?such as from topo.colors(n) and etc. but still never found it. For instance, from the help menu. ########################################### # Volcano data visualized as matrix. Need to transpose and flip # matrix horizontally. image(t(volcano)[ncol(volcano):1,]) # A prettier display of the volcano x <- 10*(1:nrow(volcano)) y

I am trying to create a topographic map of an island - the filled.contour function works fine except i am experiencing difficulty trying to represent the sea properly. Basically I want the default colour blue for any instance where z=0, if I simply use the default topo.color I get shades of blue for z values up to 220 metres. Is there a way in which I can specify terrain.color for all values of

Hi all, I'm trying to generate a grid of four plots. The first 2 appear just fine, but the final 2 will not appear in the grid, instead overwriting the first two. Any ideas on how to get them all in the same window would be greatly appreciated. Cheers, Jonathan library(fields) par(mfrow=c(2,2)) #2x2 plot windows plot(c(2,4),c(2,2)) # works fine plot(c(2,4),c(2,2)) # works fine

I'm trying to find a way to fit a polynomial of degree n in x and y to a set of x, y, and z data that I have and obtain the coefficients for the terms of the fitted polynomial. However, when I try to use the surf.ls function I'm getting odd results. > x <- seq(0, 10, length=50) > y <- x > f <- function (x, y) {x^2 + y} > library(spatial) > test <-

Dear List, Is there a color palette avaliable similar to what is used in satellite ocean color imagery? I.e. a gradient with blue on one end and red on the other, with yellow in the middle? I have tried topo.colors(n) but that comes out more yellow on the end. I am looking for something similar to what is found on the CoastWatch web page:

Hello all, I've tried to reproduce the contour plot that appears in the book of Venables and Ripley, at page 255. Is a F-statistic surface and a confidence region for the regression parameters of a non-linear model. It uses the stormer data that are in the MASS package. I haven't been able to reproduce the plot either in R ( version 1.5 ) and S. It makes the axes and it puts the

Although the 'spatial' documentation doesn't mention that extractAIC works, it does seem to give an output. I may have misunderstood, but shouldn't the following give at least the same d.f.? > library(spatial) > data(topo, package="MASS") > extractAIC(surf.ls(2, topo)) [1] 46.0000 437.5059 > extractAIC(lm(z ~ x+I(x^2)+y+I(y^2)+x:y, topo)) [1]

Hi, Is there a way to plot more than one trend surface using the functions contourplot() and wireframe(). I have found an add=T in contour(), but no equivalent argument in contourplot() and wireframe()? I have taken the example 11-2 (pages 441-451) from Design and analysis of experiments (Montgomery 2001, 5th edition) to see if this could be done in R. I have managed to plot individual

Dear useRs, I got stuck trying to generate a palette of topographic colors that would satisfy these two requirements: - the pallete must be 'anchored' at 0 (just like on a map), with light blue/lawn green corresponding to data values close to 0 (dark blue to light blue for negative values, green-yellow-brown for positive values) - the brown must get darker for higher positive

I have a huge dataset(15k X 18) and tried to use the heatmap in R to examine the patterns. However, I found that heatmap and heatmap.2 gave me completely different outputs. Here are the codes: ------------ > dim(as.matrix(data.dcpm)) [1] 15462??? 18 > > heatmap(as.matrix(data.dcpm), col=topo.colors(100)) > heatmap.2(as.matrix(data.dcpm), col=topo.colors(100), key=TRUE,

Can anyone please hazard a guess at an estimate for a poor old squirrel hunter with a Very Very Dumb Question? Is wine likely to be able to install and run any of the proprietary GPS-interfacing topo map programs (DeLorme, Garmin, Mapquest, et al.) at any roughly predictable future date? The season opens in three weeks, my GPS (Garmin's etrex vista) is full -- and it still contains road maps

Dear list members I'm currently working on some topographic (elevation) data, and was somewhat surprised that the 'topo.colors' and 'terrain.colors' are of little to no use here. The problem is that these functions only return a palette of colours; they don't map depth values to colours. So if I plot (using 'image', 'persp' or similar functions) and

Hello all, The subject line is a little ambitious, although that is my ultimate goal, to be able to run the National Geographic TOPO! program to look at maps of Arizona and California on my laptop using only Linux. I don't even own a copy of Windows, nor do I desire to, so hopefully Wine will be my friend. So far it isn't though. I haven't even got as far as trying to run TOPO! I

Dear all, I have computed a digital terrain model from a set of points (x, y, z) using the function interp() in package akima. I want to predict flooded surfaces given target values of z. I can display the flooded surfaces with contour() or image(), but I don't know how to get the polygons delimiting the surfaces. Did anyone write a function for this purpose ? Best regards, Renaud --

Hi everyone. I have a vector like this: x = c(1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,2,2,2,2,2,2,2,2) I would like to associate a colour to each of these entry. For example, I could use /topo.colors(3)/ (since I have 3 groups). I know it is easy to do this with /if/else/ statements, but I would like to find a proper way to do this. Thanks in advance, Phil -- View

Dear R users, I have created a Loess surface in R, in which x is relative longitude by miles, y is relative latitude by miles, and z is population density at the neighborhood level. The purpose is to identify some population centers in the region. I'm wondering if there is a way to determine the coordinates (x,y) of each center, so I can know exactly where they are. Let me use the