search for: extrap

...cessing analysis. Currently, it only runs with user-defined discretization parameter. I would like to implement an adaptive scheme [1] and provide the following improvements, 1) obtain an estimate of the error by fitting the result against a series of mesh sizes with the quadratic model, and extrapolate at y = 0. (quite straight forward) 2) adapt "dynamically" the set of mesh sizes to fulfill a final accuracy condition, between a starting value (a rule-of thumb estimate is given by the problem values). The lower limit of y should also be constrained by the resources (again,...

...with the grass v.out.ascii command) : user>border_limite<-read.table("/home/lionel/rwork/poly_test.txt",header=FALSE) user>polygone<-list(x=border_limite[,1],y=border_limite[,2]) So now I have a list of x,y coordinates to limit my work area. If I call the function krige with extrap=FALSE like this user>grid2.krige<-krige(grid2.point,logtab.point,'lz', logtab.Exp,maxdist=NULL,extrap=FALSE) [ where grid2.point is a point object to store prediction, logtab.point a point object containing points data, 'lz' is the variable name in logtab.point, logtab.Ex...

Hello, I have a long list of x-, y- and z-data and try to generate a heatmap. Obviously there are several data with identical x- and y-values. I get the following error message: Error in interp.old(x, y, z, xo = xo, yo = yo, ncp = 0, extrap = extrap, : duplicate data points: need to set 'duplicate = ..' Unfortunately there seems no help screen on "duplicate". I'd prefer to average the z-values in case there are identical x/y-values. Is that possible? If necessary for an answer I'll copy the short script...

...create a grid, I used "interp" from the "akima" package up until now. As mentioned in the header, I run into problems when trying the following: grid <- akima::interp(M$AM,M$Irradiance,M$PR, duplicate="mean"); Error in interp.old(x, y, z, xo = xo, yo = yo, ncp = 0, extrap = extrap, : scales of x and y are too dissimilar M$Irradiance constists mostly of 3 digit integers, whereas M$AM of decimal numbers. Now, is there another function like interp that can handle this? I could not find a clue in the doc. Should I look deeper into the doc? Maybe transform the y axi...

Dear R Users, Using the following R-script I created the first image > require(akima) > require(spatial) > dep <- interp(long, lat, depth, xo=seq(1,990,10), yo=seq(1,990,10), + extrap=FALSE, ncp=0,duplicate = "mean", dupfun = NULL) http://r.789695.n4.nabble.com/file/n3431391/Rpics.bmp Where "long" are x-coordinates between 1 and 1000, "lat" are y-cordinates between 1 and 1000, and depth are depth values corresponding to the x and y coordinates....

...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...

...with the contour() function. If have x,y and z data. All are arrays. X and Y are sampled in an orderly fashion on a grid (a circular sub-area of a grid - see plot). I'm trying to use interp() to get x and y arrays and a z matrix that can be fed to contour(). This is the command: interp(x,y,z,extrap=F,linear=FALSE,duplicate='mean') In the result there are, consistently, some discontinuities. This happens always in the 'middle' of the data. I've uploaded a plot that might clarify the problem: http://examples.attic.sent.com/example.png As you can see the middle of the plot...

...kage. Here's the code I use to create the Krig object: =========== Snip! =============================== dCurr <- sqlQuery(ds,"select x,y,acmi50 from public.cc_output" ) fitCurr <- Tps(dCurr[1:2],dCurr$acmi50, scale.type="unscaled") surface(fitCurr,type="C", extrap=TRUE, main="Median ACMI, 1961-1990", xlab="", ylab="", levels=evens) =============================================== Ultimately, I want a table of XY locations and their appropriate value from the surface. From that, I can do further statistics. The XY locations ar...

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

...; -.5 ) expiries.formated <- format(as.Date(levels(factor(expiries)), format = '%y%m%d'), "%B %d, %Y") fractionofyear.levels <- levels(factor(puts$maturity)) xyz <- with(puts, interp(x=maturity, y=delta*100, z=IV*100, xo=sort(unique(maturity)), extrap=FALSE )) with(xyz, persp3d(x,y,z, col=heat.colors(length(z))[rank(z)], xlab='maturity', ylab='delta', zlab='IV', main='IV Surface')) putsplot <- ggplot(puts, aes(delta, IV, group = factor(maturity), color = factor(maturity))) + labs(x = &qu...

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'm new on R and this mailing list. We work on spatial rainfall estimation with R and Grass. We have a problem with the krige function from the sgeostat package. We would like to limit the estimated area with a polygon limit. I use a 50 points polygon to describe my work area. The krige function work quiet well without limit. But if I use this option I have the following error

Hi, I have a sparse matrix.I want to fill values into the entries whose value is 0.The new generated values should come from the interpolation of the values have existed.Does R provide such interpolation functions which operate on Matrix, for example ,such a matrix below 0 0 0 0 2.3 0 0 0 0 0 0 3.1 0 0 0 0 1.4 0 0 0 0 0 0 0 0 0 0 1.1 0 0 0 0 0 0 0 0 0 0 0 4

To all, Apologies if this question has already been asked but I can't find anything. I can't seem to think of more specific search terms. I want to display/create a file of a pure plot with a specific height and width. I want to utilise every single pixel inside the axes. I do not want to display any margins, legends, axes, titles or spaces around the edges. Is this possible?