From: Sander Oom <slist_at_oomvanlieshout.net>

Date: Fri 27 May 2005 - 23:42:43 EST

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 Received on Fri May 27 23:48:12 2005

Date: Fri 27 May 2005 - 23:42:43 EST

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I assume this has been superseded by the ternaryplot{vcd} function!?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 Received on Fri May 27 23:48:12 2005

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