\name{plot.phylo}
\alias{plot.phylo}
\alias{plot.multiPhylo}
\title{Plot Phylogenies}
\usage{
\method{plot}{phylo}(x, type = "phylogram", use.edge.length = TRUE,
    node.pos = NULL, show.tip.label = TRUE, show.node.label = FALSE,
    edge.color = "black", edge.width = 1, edge.lty = 1, font = 3,
    cex = par("cex"), adj = NULL, srt = 0, no.margin = FALSE,
    root.edge = FALSE, label.offset = 0, underscore = FALSE,
    x.lim = NULL, y.lim = NULL, direction = "rightwards",
    lab4ut = "horizontal", tip.color = "black", ...)
\method{plot}{multiPhylo}(x, layout = 1, ...)
}
\arguments{
  \item{x}{an object of class \code{"phylo"} or of class
    \code{"multiPhylo"}.}
  \item{type}{a character string specifying the type of phylogeny to be
    drawn; it must be one of "phylogram" (the default), "cladogram",
    "fan", "unrooted", "radial" or any unambiguous abbreviation of
    these.}
  \item{use.edge.length}{a logical indicating whether to use the edge
    lengths of the phylogeny to draw the branches (the default) or not
    (if \code{FALSE}). This option has no effect if the object of class
    \code{"phylo"} has no `edge.length' element.}
  \item{node.pos}{a numeric taking the value 1 or 2 which specifies the
    vertical position of the nodes with respect to their descendants. If
    \code{NULL} (the default), then the value is determined in relation
    to `type' and `use.edge.length' (see details).}
  \item{show.tip.label}{a logical indicating whether to show the tip
    labels on the phylogeny (defaults to \code{TRUE}, i.e. the labels
    are shown).}
  \item{show.node.label}{a logical indicating whether to show the node
    labels on the phylogeny (defaults to \code{FALSE}, i.e. the labels
    are not shown).}
  \item{edge.color}{a vector of mode character giving the colours used
    to draw the branches of the plotted phylogeny. These are taken to be
    in the same order than the component \code{edge} of \code{phy}. If
    fewer colours are given than the length of \code{edge}, then the
    colours are recycled.}
  \item{edge.width}{a numeric vector giving the width of the branches of
    the plotted phylogeny. These are taken to be in the same order than
    the component \code{edge} of \code{phy}. If fewer widths are given
    than the length of \code{edge}, then these are recycled.}
  \item{edge.lty}{same than the previous argument but for line types;
    1: plain, 2: dashed, 3: dotted, 4: dotdash, 5: longdash, 6: twodash.}
  \item{font}{an integer specifying the type of font for the labels: 1
    (plain text), 2 (bold), 3 (italic, the default), or 4 (bold
    italic).}
  \item{cex}{a numeric value giving the factor scaling of the tip and
    node labels (Character EXpansion). The default is to take the
    current value from the graphical parameters.}
  \item{adj}{a numeric specifying the justification of the text strings
    of the labels: 0 (left-justification), 0.5 (centering), or 1
    (right-justification). This option has no effect if \code{type =
      "unrooted"}. If \code{NULL} (the default) the value is set with
    respect of \code{direction} (see details).}
  \item{srt}{a numeric giving how much the labels are rotated in degrees
    (negative values are allowed resulting in clock-like rotation); the
    value has an effect respectively to the value of
    \code{direction} (see Examples). This option has no effect if
    \code{type = "unrooted"}.}
  \item{no.margin}{a logical. If \code{TRUE}, the margins are set to
    zero and the plot uses all the space of the device (note that this
    was the behaviour of \code{plot.phylo} up to version 0.2-1 of `ape'
    with no way to modify it by the user, at least easily).}
  \item{root.edge}{a logical indicating whether to draw the root edge
    (defaults to FALSE); this has no effect if `use.edge.length = FALSE'
    or if `type = "unrooted"'.}
  \item{label.offset}{a numeric giving the space between the nodes and
    the tips of the phylogeny and their corresponding labels. This
    option has no effect if \code{type = "unrooted"}.}
  \item{underscore}{a logical specifying whether the underscores in tip
    labels should be written as spaces (the default) or left as are (if
    \code{TRUE}).}
  \item{x.lim}{a numeric vector of length one or two giving the limit(s)
    of the x-axis. If \code{NULL}, this is computed with respect to
    various parameters such as the string lengths of the labels and the
    branch lengths. If a single value is given, this is taken as the
    upper limit.}
  \item{y.lim}{same than above for the y-axis.}
  \item{direction}{a character string specifying the direction of the
    tree. Four values are possible: "rightwards" (the default),
    "leftwards", "upwards", and "downwards".}
  \item{lab4ut}{(= labels for unrooted trees) a character string
    specifying the display of tip labels for unrooted trees: either
    \code{"horizontal"} where all labels are horizontal (the default),
    or \code{"axial"} where the labels are displayed in the axis of the
    corresponding terminal branches. This option has an effect only if
    \code{type = "unrooted"}.}
  \item{tip.color}{the colours used for the tip labels, eventually
    recycled (see examples).}
  \item{layout}{the number of trees to be plotted simultaneously.}
  \item{\dots}{further arguments to be passed to \code{plot} or to
    \code{plot.phylo}.}
}
\description{
  These functions plot phylogenetic trees on the current graphical
  device.
}
\details{
  If \code{x} is a list of trees (i.e., an object of class
  \code{"multiPhylo"}), then any further argument may be passed with
  \code{...} and could be any one of those listed above for a single
  tree.

  The font format of the labels of the nodes and the tips is the same.

  If \code{no.margin = TRUE}, the margins are set to zero and are not
  restored after plotting the tree, so that the user can access the
  coordinates system of the plot.

  The option `node.pos' allows the user to alter the vertical position
  (i.e. ordinates) of the nodes. If \code{node.pos = 1}, then the
  ordinate of a node is the mean of the ordinates of its direct
  descendants (nodes and/or tips). If \code{node.pos = 2}, then the
  ordinate of a node is the mean of the ordinates of all the tips of
  which it is the ancestor. If \code{node.pos = NULL} (the default),
  then its value is determined with respect to other options: if
  \code{type = "phylogram"} then `node.pos = 1'; if \code{type =
    "cladogram"} and \code{use.edge.length = FALSE} then `node.pos = 2';
  if \code{type = "cladogram"} and \code{use.edge.length = TRUE} then
  `node.pos = 1'. Remember that in this last situation, the branch
  lengths make sense when projected on the x-axis.

  If \code{adj} is not specified, then the value is determined with
  respect to \code{direction}: if \code{direction = "leftwards"} then
  \code{adj = 1} (0 otherwise).

  If the arguments \code{x.lim} and \code{y.lim} are not specified by the
  user, they are determined roughly by the function. This may not always
  give a nice result: the user may check these values with the
  (invisibly) returned list (see ``Value:'').

  If you resize manually the graphical device (windows or X11) you may
  need to replot the tree.
}
\note{
  The argument \code{asp} cannot be passed with \code{\dots}.
}
\value{
  \code{plot.phylo} returns invisibly a list with the following
  components which values are those used for the current plot:

  \item{type}{}
  \item{use.edge.length}{}
  \item{node.pos}{}
  \item{show.tip.label}{}
  \item{show.node.label}{}
  \item{font}{}
  \item{cex}{}
  \item{adj}{}
  \item{srt}{}
  \item{no.margin}{}
  \item{label.offset}{}
  \item{x.lim}{}
  \item{y.lim}{}
  \item{direction}{}
  \item{tip.color}{}
  \item{Ntip}{}
  \item{Nnode}{}
}
\author{Emmanuel Paradis}
\seealso{
  \code{\link{read.tree}}, \code{\link{add.scale.bar}},
  \code{\link{axisPhylo}}, \code{\link{nodelabels}},
  \code{\link{edges}}, \code{\link[graphics]{plot}} for the basic
  plotting function in R
}
\examples{
### An extract from Sibley and Ahlquist (1990)
cat("(((Strix_aluco:4.2,Asio_otus:4.2):3.1,",
   "Athene_noctua:7.3):6.3,Tyto_alba:13.5);",
   file = "ex.tre", sep = "\n")
tree.owls <- read.tree("ex.tre")
plot(tree.owls)
unlink("ex.tre") # delete the file "ex.tre"

### Show the types of trees.
layout(matrix(1:6, 3, 2))
plot(tree.owls, main = "With branch lengths")
plot(tree.owls, type = "c")
plot(tree.owls, type = "u")
plot(tree.owls, use.edge.length = FALSE, main = "Without branch lengths")
plot(tree.owls, type = "c", use.edge.length = FALSE)
plot(tree.owls, type = "u", use.edge.length = FALSE)
layout(matrix(1))

data(bird.orders)
### using random colours and thickness
plot(bird.orders,
     edge.color = sample(colors(), length(bird.orders$edge)/2),
     edge.width = sample(1:10, length(bird.orders$edge)/2, replace = TRUE))
title("Random colours and branch thickness")
### rainbow colouring...
X <- c("red", "orange", "yellow", "green", "blue", "purple")
plot(bird.orders,
     edge.color = sample(X, length(bird.orders$edge)/2, replace = TRUE),
     edge.width = sample(1:10, length(bird.orders$edge)/2, replace = TRUE))
title("Rainbow colouring")
plot(bird.orders, type = "c", use.edge.length = FALSE,
     edge.color = sample(X, length(bird.orders$edge)/2, replace = TRUE),
     edge.width = rep(5, length(bird.orders$edge)/2))
segments(rep(0, 6), 6.5:1.5, rep(2, 6), 6.5:1.5, lwd = 5, col = X)
text(rep(2.5, 6), 6.5:1.5, paste(X, "..."), adj = 0)
title("Character mapping...")
plot(bird.orders, "u", font = 1, cex = 0.75)
data(bird.families)
plot(bird.families, "u", lab4ut = "axial", font = 1, cex = 0.5)
plot(bird.families, "r", font = 1, cex = 0.5)
### cladogram with oblique tip labels
plot(bird.orders, "c", FALSE, direction = "u", srt = -40, x.lim = 25.5)
### facing trees with different informations...
tr <- bird.orders
tr$tip.label <- rep("", 23)
layout(matrix(1:2, 1, 2), c(5, 4))
plot(bird.orders, "c", FALSE, adj = 0.5, no.margin = TRUE, label.offset = 0.8,
     edge.color = sample(X, length(bird.orders$edge)/2, replace = TRUE),
     edge.width = rep(5, length(bird.orders$edge)/2))
text(7.5, 23, "Facing trees with\ndifferent informations", font = 2)
plot(tr, "p", direction = "l", no.margin = TRUE,
     edge.width = sample(1:10, length(bird.orders$edge)/2, replace = TRUE))
### Recycling of arguments gives a lot of possibilities
### for tip labels:
plot(bird.orders, tip.col = c(rep("red", 5), rep("blue", 18)),
     font = c(rep(3, 5), rep(2, 17), 1))
plot(bird.orders, tip.col = c("blue", "green"),
     cex = 23:1/23 + .3, font = 1:3)
co <- c(rep("blue", 9), rep("green", 35))
plot(bird.orders, "f", edge.col = co)
plot(bird.orders, edge.col = co)
layout(1)
}
\keyword{hplot}