You can use the akima package to interpolate to a regular grid, then plot that. Another choice is to fit a smooth surface, using any number of smoothers available in R and CRAN.
Andy > From: Laura Quinn > > 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$y, data$value) : > increasing x and y values expected > > I have re-ordered the matrix so that the x values are increasing, but > these do not necessarrily correspond with increasing y values > (as this is > not a regular grid)...can anyone offer a way around this?? > > Laura Quinn > Institute of Atmospheric Science > School of Earth and Environment > University of Leeds > Leeds > LS2 9JT > > tel: +44 113 343 1596 > fax: +44 113 343 6716 > mail: [EMAIL PROTECTED] > > ______________________________________________ > 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 > > > ______________________________________________ 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