Hi: Here's a simple example:
a <- rnorm(100) b <- rnorm(100, 2) c <- rnorm(100, 5) x <- 1:100 library(lattice) xyplot(a + b + c ~ x, type = 'l') HTH, Dennis On Fri, Jun 18, 2010 at 12:45 AM, David Wyllie <david.wyl...@ndm.ox.ac.uk>wrote: > Hi > > is it possible to fit a trend line (or some other panel function) through > each of multiple data series plotted on the same graph? Specifically, while > one can do something like > xyplot(a+b+c~x) > which plots three series, a,b & c, but can one automatically fit lines > through each of them? > > > I suppose one could generate three more variables afit, bfit, and cfit with > a model & predict and then plot them, but wondered if there was an easier > way. > > > Thank you for any advice. Here is an example: > > > # use an example panel function using smooth.spline; however, the issue > relates to all panel functions > # a panel function to fit smoothed lines through data > panel.smooth.spline <- function(x, y, > w=NULL, df, spar = NULL, cv = FALSE, > lwd=plot.line$lwd, lty=plot.line$lty,col, > col.line=plot.line$col, > type, horizontal=FALSE,... ) > { > # Deepayan Sarkar code from: > http://www.mail-archive.com/r-help@r-project.org/msg39654.html > x <- as.numeric(x) > y <- as.numeric(y) > > > ok <- is.finite(x) & is.finite(y) > > > if (sum(ok) < 1) > return() > if (!missing(col)) { > if (missing(col.line)) > col.line <- col > } > plot.line <- trellis.par.get("plot.line") > if (horizontal) { > spline <- > smooth.spline(y[ok], x[ok], > w=w, df=df, spar = spar, cv = cv, ...) > panel.lines(x = spline$y, y = spline$x, col = col.line, > lty = lty, lwd = lwd, ...) > } > else { > spline <- > smooth.spline(x[ok], y[ok], > w=w, df=df, spar = spar, cv = cv, ...) > panel.lines(x = spline$x, y = spline$y, col = col.line, > lty = lty, lwd = lwd, ...) > } > } > > > > > # a composite function combining the xyplot and smooth.spline functions > panel.composite<-function(x,y,groups, subscripts, ...) { > panel.xyplot(x,y,...) > panel.smooth.spline(x,y,...) > } > > > # generate mock data; this comprises three data series, a,b,c with means of > about 5,35, and 105. > test <- data.frame( > a = runif(100, min=0, max=10), > b = 30+runif(100, min=0, max=10), > c = 100+runif(100, min=0, max=10), > x = 1:100) > > > # illustrate data > xyplot(a + b + c ~ x, data = test, type = "p", auto.key=TRUE) > > > # plot with fits .. but actually only one fit > xyplot( > a + b + c ~ x, > panel=panel.composite, > data = test, > type = "p", > auto.key=TRUE) > > ______________________________________________ > R-help@r-project.org 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org 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.