similar to: image() plot with z not in matrix format

Dear all. I am using the akima function to produce 3d contour plots using interp based on irregular data. using the eg in the akima manual library("akima") data(akima) plot(y ~ x, data = akima, main = "akima example data") with(akima, text(x, y, formatC(z,dig=2), adj = -0.1)) ## linear interpolation akima.li <- interp(akima$x, akima$y, akima$z) image (akima.li, add=TRUE)

Hello, I'd like to make a z(x,y) plot for irregularly spaced x,y. What are routines are available in R for this purpose? Thanks, Mark

Hello again, There is any package which does Z aware (real 3D) interpolations? It can be any method (IDW, kriging or spline) but it should take into consideration not only x and y coordinates for interpolation, but also z coordinate. I looked into different packages but it seems i didn't find the right one. The ultimate goal is to import the output into a GIS (Geographical Information

Dear all; First of all, this is probably a more conceptual question than a R-related one, but still want to give it a try. When working with the interpolation function "interp" from the package akima and the triangulation function "tri.mesh" from package tripack I've got NA's for the interpolation and "error" for the triangulation. The data is arranged in a

Hello, I'm dealing with the following problem: I have a table with x and y coordinates and corresponding values of a mineral concentration, let's call it z. Can someone provide me a short step-by-step manual for the steps necessary to get a contour map? How to sort and interpolate my matrix to an equidistant grid which can afterwards be plotted by contour(x,y,z)? (e.g. fill the

Hi, I'm currently hunting a bug in the akima library, especially in the code behind the interpp.old function (bi-variate linear interpolation). It is based on a triangulation algorithm, interpolation at a given point needs to know the triangle which contains this point, then the interpolation is a straightforward calculation based on the three vertexes. The problem is: Sometimes the triangle

Dear all, I'm trying to interpolate a dataset to give it twice as many values (I'm giving the dataset a finer resolution by interpolating from 1 degree to 0.5 degrees) to match that of a corresponding dataset. I have the data in both a data frame format (longitude column header values along the top with latitude row header values down the side) or column format (in the format latitude,

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),

Readers, I have looked at various documents hosted on the web site; I couldn't find anything on interpolation. So I started r and accessed the help (help.start()). (by the way is it possible to configure r to open help in opera instead of firefox?) Initially I read the help for the akima package but couldn't understand it. Next I tried the asplines package help. I tried to copy the

Hello, I have a x,y,z file.Z is not corresponding to a simple analytical function of x and y (see below). I am trying to find the minimum location of this surface and the z value corresponding to this location by a spline interpolation or from a polynomial fit. I tried with the akima package but as the location of the point I am looking for (the minimum) is outside of the convex hull it's

Hi there, I have been using the Tps function (within the Fields package) for a while now to interpolate different sedimentary units. Due to the method of formation of the units I know that at some edges the thickness of the unit decreases to zero. I was wondering if there was someway to specify that the interpolation only occurs within the convex hull of the data, outside of which the the values

Hello all, I'm very new to R and am having some trouble with the results of the interp function. I'm trying to produce a chart roughly akin to a weather map with natural looking filled contours over a large region of the south pacific. I've got a list of points and values to be mapped to those points and I use the interp function as follows: tab<-read.table("data.txt")

Hi everybody. i have 2 datasets : one with a long grid a lat grid and a bathymetry grid the second one only has the long and lat coordinates. So i want to know the bathymetry associated to the second dataset. I thought it was a good idea to do an interpolation between the two datasets. I find a script doing that on matlab but i want to do it on R. Do you how to do it? for ii =

Dear all! I'm using R 2.12.1 in Ubuntu 10.04. Problem is that when using functions like interp (package akima) and akimaInterp (package fUtilities), I get different results every time for the same data set. I've checked the interpolated results, and two examples (in attachment) have different sum of NA values. Also when I subtract the x,y,z values from two interpolations of the same data

I have a huge data set in the form of            V1           V2         V3   V4     V5  V6 1     201005010000201005010000 1.68291.38 1  0 2     201005010000201005010300 0.93335.10 1  0 3     201005010000201005010600 2.25 57.38 1  0 4     201005010000201005010900 0.43 13.76 1  0 5     201005010000201005011200 0.74101.14 1  0 I am interested in interpolating it on an hour basis(it's for avery

hello, is it possible to do something like splinefun(x,y), but with a 3rd dim? for example, if i have a 2-dim system like: x<-1:100 y<-rexp(100,1) func<-splinefun(x,sort(y)) func(n) # returns interpolated value of y (after sorting) given x=n # i can check this by: plot(x,sort(y)) lines(spline(x,sort(y))) Can i do the same thing with an x,y, and z? i have found the akima

Hi, I have three matrices (X,Y,P) with the same dimension. The X,Y grid is regular and I want to perform linear interpolation to pick out certain points. In matlab appropriate call is something like Pout=interp2(X,Y,P,Xout,Yout, method="linear") where Xout and Yout are the locations where I want the Pout data (typically a different grid). (Scipy has this routine in

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,

As part of a project I am doing, I had to present a 2D table as a surface. This was fairly straightforward (using persp), but I needed to interpolate points to make it sort of pretty. This was done by using quadratic interpolation between the existing points to smooth out the surface a bit. As I couldn't find an R function that did this, I wrote an admittedly nasty pair of functions that

What package/code could I use to create a 3-d surface graph of the predicted values over two of the explanatory variables' coefficients? Jim James Bang Department of Economics University of Illinois Well I AM missing the back of my head.you COULD cut me a little slack! -Homer Simpson