On Fri, 6 Jan 2006, Jan Verbesselt wrote: > Dear R help, > > We are trying to visualise spatial raster data. We have per line, X & Y > coordinates and Z(data). How could we visualise this type of data? We > also would like to add extra data points to this plot based on new X,Y > and Z data. > > We used the following function but would like to use only the graph in > the upper right corner (spatial one) . Similar to the graph cfr. > http://www.est.ufpr.br/geoR/geoRdoc/vignette/geoRintro/geoRintrose3.html#x4-60003.1 > > geo_iRVI <- as.geodata(pixels_blok,coords.col=2:3, data.col=4) > plot(geo_iRVI) > > How can this plot be optimized? And can we add other points to it? > > Another solution could be: > filled.contour(AVG,color=terrain.colors, xlab="Longitude (°)", > ylab="Latitude (°)) but therefore the data needs to be organised > differently, not per line of X,Y coordinates but in a raster form. > > Can anyone advise functions to visualise spatial raster data optimally?
The SpatialGrid and SpatialPixels classes in the sp package provide a starting point: library(sp) xygrid <- expand.grid(1:25, 1:25) xysubset <- xygrid[1:400,] xysp <- SpatialPixels(SpatialPoints(xysubset)) xyz <- SpatialPixelsDataFrame(xysp, data=data.frame(z=runif(400))) image(xyz, xlim=c(0,26), ylim=c(0,26)) xyadd <- xygrid[501:625,] xyspadd <- SpatialPixels(SpatialPoints(xyadd)) xyzadd <- SpatialPixelsDataFrame(xyspadd, data=data.frame(z=runif(125))) image(xyzadd, add=TRUE) SpatialPixels need to be regularly spaced, but do not have to be a full rectangular grid, and have an image() method. You may find the R-sig-geo mailing list more appropriate for this kind of question, access via the "Spatial" Task View on CRAN. > > thanks, > Jan > > windows R 2.2 > library(geoR) > library(akima) > -- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: [EMAIL PROTECTED] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
