similar to: Contents of R-help digest.-contouring

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 Folks, I'm probably overlooking some small point, but can't see it. Trying the "Local trend surfaces" example from p.437 of MASS (3rd edn) by V&R, all goes well until the line contour(topo.mar$x, topo.mar$y, topo.lo$fit, levels=seq(700,1000,25), xlab="fi t", ylab="") which produces the response: Error in contour.default(topo.mar$x,

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]]

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

Dear all, I wonder about what could actually be possible with the function "contour": 1/ - the definition of contour lines is most often meaningless when the contours are drawn in areas where no real data points exist. It can however happen that irregular distributions lead to more or less irregular clouds of data points. Interpolations (eg: loess regression, GLM, etc...) are however

Hi all, I'm trying to make multiple lattice contour plots which have the same color key, to allow good comparisons. However, I run into some problems when fitting the plots to the color key. Basically my strategy to tackle this problem was: 1) define a color key for all plots; 2) calculate the variable range for each plot; 3) calculate the range of colors from the color key that correspond

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

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

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

Dear R-Listers, I have spatial data on an equidistant rectangular grid, similar to topographic data. I know that there are quite a few R-packages or base functions that provide nice iso-contours plot, but I don't want a plot, just the smoothed isocontour line of ONE level (e.g. 10 mm). Data sets are large, so it would be preferable if the availability of regular grid data could be exploited,

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:

The locfit library is now available through CRAN, in the Contributed R Code directory. Locfit fits local regression, likelihood and density estimation models, in the spirit of loess but with many additional features. To install, unpack the locfit_19980309.tar.gz file, and R INSTALL locfit Most of the functionality and examples on my home page http://cm.bell-labs.com/stat/project/locfit/ should

The locfit library is now available through CRAN, in the Contributed R Code directory. Locfit fits local regression, likelihood and density estimation models, in the spirit of loess but with many additional features. To install, unpack the locfit_19980309.tar.gz file, and R INSTALL locfit Most of the functionality and examples on my home page http://cm.bell-labs.com/stat/project/locfit/ should

Hello, I'm almost positive R can do the following, I just haven't hit upon the right package or search terms, however. Here's what I'm after: I've got concentration output from two different models that I want to qualitatively compare in a contour plot (or some variant of a contour plot). The problem as I see it is that the data is not gridded is the usual regular fashion,

Dear R'Helpers and Colleagues, I have looked in the documentation, asked to some colleagues in the lab, but was unable to solve the following difficulty. I am running R on a iMac G5 with OS 10.4. The file below (73 rows x 144 col) shows the values of a climatic index on the globe with a grid of 2,5 ? x 2,5 ? (NA = no value): ? With image() and map() and running the following

Apologies for the mass mailing today! I am attempting to produce a contour plot for phsical data on a map matrix. I have a small number of data points which each has an (x,y) co-ordinate together with a corresponding value which I would like to cvreate a contour plot for. I have tried the following code: contour(data$x,data$y,data$value) but am told: Error in contour.default(data$x, data$y,

Hi all, I'm trying to draw a contour plot with rounded (smoothed) contour lines instead of sharp angles; when the grid consists of only a few points in x- and y- axis, the resulting contour is in facts rather ugly since very sharp angles may appear. I did not find any way to do it, by using either "contour" or "contourplot" (from the lattice package), I wonder if there

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]

Dear, I have XYZ data available in a MySQL database. I get it out, can plot the data with the plot() function, load it into a geoR datastructure. But what I actually would like to do is a simple contouring of the data based on a no Kriging interpolation such as TIN based. I know the first thing I shold do is interpolate a full matrix for the region I have my points for, then contour should