Hi Jari, I assume this has been superseded by the ternaryplot{vcd} function!?
Thanks, Sander. Jari Oksanen wrote: > Sander, > > Just a quick note before I go to the field. > > I attach a tri.R file for drawing ternary plots. The base function was > posted to R News someday. One thing that I added was option to plot > nothing (type="n") plus (invisible) return of plotting coordinates. This > means that you can take the coordinates for drawing segments (in > original values), feed them through this functions, and you get > translated coordinates to use ordinary segments or lines commands to > overlay your lines into an existing ternary plot. > > We used this in an Applied Vegetation Science paper (Hellström as the > first author) to overlay arrows onto ternary plots. > > cheers, jari oksanen > > > ------------------------------------------------------------------------ > > "tri" <- > function(a, f, m, symb = 2, grid = F, ...) > { > ta <- paste(substitute(a)) > tf <- paste(substitute(f)) > tm <- paste(substitute(m)) > > tot <- 100/(a + f +m) > b <- f * tot > y <- b * .878 > x <- m * tot + b/2 > par(pty = "s") > oldcol <- par("col") > plot(x, y, axes = F, xlab = "", ylab = "", xlim = c(-10, 110), ylim > = c(-10, 110), type = "n", ...) > points(x,y,pch=symb) > par(col = oldcol) > trigrid(grid) > text(-5, -5, ta) > text(105, -5, tm) > text(50, 93, tf) > par(pty = "m") > invisible(cbind(x,y)) > } > ______________________________________________ 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