| % File src/library/graphics/man/arrows.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2009 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{arrows} |
| \title{Add Arrows to a Plot} |
| \usage{ |
| arrows(x0, y0, x1 = x0, y1 = y0, length = 0.25, angle = 30, |
| code = 2, col = par("fg"), lty = par("lty"), |
| lwd = par("lwd"), \dots) |
| } |
| \alias{arrows} |
| \arguments{ |
| \item{x0, y0}{coordinates of points \bold{from} which to draw.} |
| \item{x1, y1}{coordinates of points \bold{to} which to draw. At least |
| one must the supplied} |
| \item{length}{length of the edges of the arrow head (in inches).} |
| \item{angle}{angle from the shaft of the arrow to the edge of the |
| arrow head.} |
| \item{code}{integer code, determining \emph{kind} of arrows to be |
| drawn.} |
| \item{col, lty, lwd}{\link{graphical parameters}, possible vectors. |
| \code{NA} values in \code{col} cause the arrow to be omitted.} |
| \item{\dots}{\link{graphical parameters} such as \code{xpd} and the line |
| characteristics \code{lend}, \code{ljoin} and \code{lmitre}: |
| see \code{\link{par}}.} |
| } |
| \description{ |
| Draw arrows between pairs of points. |
| } |
| \details{ |
| For each \code{i}, an arrow is drawn between the point \code{(x0[i], |
| y0[i])} and the point \code{(x1[i], y1[i])}. The coordinate vectors |
| will be recycled to the length of the longest. |
| |
| If \code{code = 1} an arrowhead is drawn at \code{(x0[i], y0[i])} and if |
| \code{code = 2} an arrowhead is drawn at \code{(x1[i], y1[i])}. If |
| \code{code = 3} a head is drawn at both ends of the arrow. Unless |
| \code{length = 0}, when no head is drawn. |
| |
| The \link{graphical parameters} \code{col}, \code{lty} and \code{lwd} |
| can be vectors of length greater than one and will be recycled if |
| necessary. |
| |
| |
| The direction of a zero-length arrow is indeterminate, and hence so is |
| the direction of the arrowheads. To allow for rounding error, |
| arrowheads are omitted (with a warning) on any arrow of length less |
| than 1/1000 inch. |
| } |
| \references{ |
| Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) |
| \emph{The New S Language}. |
| Wadsworth & Brooks/Cole. |
| } |
| \seealso{ |
| \code{\link{segments}} to draw segments. |
| } |
| \note{The first four arguments in the comparable S function are named |
| \code{x1, y1, x2, y2}. |
| } |
| \examples{ |
| x <- stats::runif(12); y <- stats::rnorm(12) |
| i <- order(x, y); x <- x[i]; y <- y[i] |
| plot(x,y, main = "arrows(.) and segments(.)") |
| ## draw arrows from point to point : |
| s <- seq(length(x)-1) # one shorter than data |
| arrows(x[s], y[s], x[s+1], y[s+1], col = 1:3) |
| s <- s[-length(s)] |
| segments(x[s], y[s], x[s+2], y[s+2], col = "pink") |
| } |
| \keyword{aplot} |