| arrows {graphics} | R Documentation |
Add Arrows to a Plot
Description
Draw arrows between pairs of points.
Usage
arrows(x0, y0, x1 = x0, y1 = y0, length = 0.25, angle = 30,
code = 2, col = par("fg"), lty = par("lty"),
lwd = par("lwd"), ...)
Arguments
x0, y0 |
coordinates of points from which to draw. |
x1, y1 |
coordinates of points to which to draw. At least one must the supplied |
length |
length of the edges of the arrow head (in inches). |
angle |
angle from the shaft of the arrow to the edge of the arrow head. |
code |
integer code, determining kind of arrows to be drawn. |
col, lty, lwd |
graphical parameters, possible vectors.
|
... |
graphical parameters such as |
Details
For each i, an arrow is drawn between the point (x0[i],
y0[i]) and the point (x1[i], y1[i]). The coordinate vectors
will be recycled to the length of the longest.
If code = 1 an arrowhead is drawn at (x0[i], y0[i]) and if
code = 2 an arrowhead is drawn at (x1[i], y1[i]). If
code = 3 a head is drawn at both ends of the arrow. Unless
length = 0, when no head is drawn.
The graphical parameters col, lty and 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.
Note
The first four arguments in the comparable S function are named
x1, y1, x2, y2.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
See Also
segments to draw segments.
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")