You can use plot(y~x,col=color.index.in.palette.defined.from(z),pch=20,type="p")
where color.index.in.palette.defined.from(z) is a function or an expression, returning either a color index in a predefined palette or any other color representation, suitable for R. This is described in ?par. I have successfuly used col=z*10 with your sample data. type="p" specifies, that points will be plotted. pch=20 says to plot them as small filled circles, sometimes I needed smaller circles, and pch=183 worked for me. The package fields and several other packages related to the spatial statistics are able to plot irregularly distributed point data and interpolate them to a regular grid (produce a 'contiguous' map). Here are some links: http://sal.uiuc.edu/csiss/Rgeo/ http://r-spatial.sourceforge.net/ You can also try RSiteSearch("spatial") or help.search("spatial") from the R console Trevor Graham wrote: > > I've got some data in a data frame arranged like this: > x y z othervariables .... > 0.1 0.2 1.7 0.01 .... > 0.2 0.2 1.3 0.23 .... > 0.2 0.3 1.1 0.43 .... > etc > > I'd like to plot a heatmap of this data, with x and y as the (x,y) coords > and z defining the colour at each point. > > I'm having difficulty finding the correct functions to use. Can anyone > make any recommendations? > > It seems straightforward to make the plot using the image function if > the data is in matrix form, but I'm not sure how to transform my xyz > data into matrix form. > > -- View this message in context: http://www.nabble.com/-R--heatmap-from-xyz-data-tf3180966.html#a8827597 Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
