arrows {base}

R Documentation

Add Arrows to a Plot

Description

segments draws a line segment and arrows draws an arrow between the point (x0[i], y0[i]) and the point (x1[i],y1[i]). If code=2 an arrowhead is drawn at (x0[i],y0[i]) and if code=1 an arrowhead is drawn at (x1[i],y1[i]). If code=3 a head is drawn at both ends of the arrow.

The graphical parameters col and lty can be used to specify a color an line texture for the line segments which make up the segments or arrows (col may be a vector).

Usage

arrows(x0, y0, x1, y1, length = 0.25, angle = 30, code = 2,
       col = par("fg"), lty = NULL, xpd = FALSE)
segments(x0, y0, x1, y1, col = par("fg"), lty = par("lty"))

Arguments

x0, y0	coordinates of points from which to draw.
x1, y1	coordinates of points to which to draw.
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, xpd	usual graphical parameters as in par.

See Also

polygon for slightly easier and less flexible line drawing and lines for the usual polygons.

Examples

x <- runif(12); y <- 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')

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