4 \title{Draw Additional Edges on a Plotted Tree}
6 \code{edges} draws edges on a plotted tree. \code{fancyarrows}
7 enhances \code{\link[graphics]{arrows}} with triangle and harpoon
8 heads; it can be called from \code{edges}.
11 edges(nodes0, nodes1, arrows = 0, type = "classical", ...)
12 fancyarrows(x0, y0, x1, y1, length = 0.25, angle = 30, code = 2,
13 col = par("fg"), lty = par("lty"), lwd = par("lwd"),
14 type = "triangle", ...)
17 \item{nodes0, nodes1}{vectors of integers giving the tip and/or node
18 numbers where to start and to end the edges (eventually recycled).}
19 \item{arrows}{an integer between 0 and 3; 0: lines (the default); 1:
20 an arrow head is drawn at \code{nodes0}; 2: at \code{nodes1}; 3:
22 \item{type}{if the previous argument is not 0, the type of arrow head:
23 \code{"classical"} (just lines, the default), \code{"triangle"},
24 \code{"harpoon"}, or any unambiguous abbreviations of these. For
25 \code{fancyarrows} only the last two are available.}
26 \item{x0, y0, x1, y1}{the coordinates of the start and end points for
27 \code{fancyarrows} (these are not recycled and so should be vectors
29 \item{length, angle, code, col, lty, lwd}{default options similar to
30 those of \code{\link[graphics]{arrows}}.}
31 \item{\dots}{further arguments passed to \code{\link[graphics]{segments}}.}
34 The first function is helpful when drawing reticulations on a phylogeny,
35 especially if computed from the edge matrix.
37 \author{Emmanuel Paradis}
39 \code{\link{plot.phylo}}, \code{\link{nodelabels}}
45 edges(10, 9, col = "red", lty = 2)
46 edges(10:11, 8, col = c("blue", "green")) # recycling of 'nodes1'
47 edges(1, 2, lwd = 2, type = "h", arrows = 3, col = "green")