Hello Hadley, Thank you (and Domenico) for your help. I'm almost there. For convenience, I'll restate the question. With the following data: a <- seq(0, 360, 5)*pi/180 ; a ac <- sin(a + (45*pi/180)) + 1 ; ac s <- seq(5, 45, 10)*pi/180 ; s asc <- lapply(s, function(x) x*cos(ac) + x*sin(ac)) ; asc
I can generate my desired plot by traditional methods with: plot(a, ac, type='l', xaxt = "n", xlab='azimuth', ylab='index') axis(1, at=seq(0,6,1), labels=round(seq(0,6,1)*180/pi),0) abline(v=c(45*pi/180, 225*pi/180)) ; par(new=TRUE) lapply(asc, function(x) {plot(a, x, type='l', xaxt = "n", yaxt = "n", xlab='', ylab='', ylim=c(0, 2)) ; par(new=TRUE)}) With ggplot2 and your suggestions I can generate the same with: p <- qplot(a, ac, geom='line') + geom_line(aes(x=a, y=asc[[1]])) + geom_line(aes(x=a, y=asc[[2]])) + geom_line(aes(x=a, y=asc[[3]])) + geom_line(aes(x=a, y=asc[[4]])) + geom_line(aes(x=a, y=asc[[5]])) + scale_x_continuous(name="azimuth") + scale_y_continuous(name="index")) But these attempts to recreate the x-axis labels both generate the following error: p + scale_x_continuous(labels=round(seq(0,6,1)*180/pi,0)) p + scale_x_continuous(breaks=seq(0,6,1), labels=round(seq(0,6,1)*180/pi,0)) Error in get("new", env = ScaleContinuous, inherits = TRUE)(ScaleContinuous, : unused argument(s) (labels = c(0, 57, 115, 172, 229, 286, 344)) And these attempts to draw reference lines both generate the following error: p + geom_vline(45*pi/180) + geom_vline(225*pi/180) p + geom_vline(0.79) + geom_vline(3.9) Error in data.frame(..., check.names = FALSE) : arguments imply differing number of rows: 73, 1 What am I missing? Thanx, DaveT. ************************************* Silviculture Data Analyst Ontario Forest Research Institute Ontario Ministry of Natural Resources [EMAIL PROTECTED] http://ofri.mnr.gov.on.ca ______________________________________________ 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.