临湖听涛 发表于 2010-3-13 02:16
Just try the following:

x1=seq(0,5,0.01)

x2=seq(5,10,0.01)

y1=x1*0-1

y2=x2-6

x=c(x1,x2)

y=c(y1,y2)

plot(x,y,

xaxt='n',yaxt='n',

xlab="",ylab="",

bty='n',type='l',

xlim=c(-1,10),ylim=c(-2,7))

arrows(-2,0,10,0)
arrows(0,-2,0,7)

trier2006 发表于 2010-3-15 08:22
7# casperyc

哈，我也学了一招。以前不知道arrows。

DescriptionDraw arrows between pairs of points.
Usagearrows(x0, y0, x1 = x0, y1 = y0, length = 0.25, angle = 30, code = 2,       col = par("fg"), lty = par("lty"), lwd = par("lwd"),       ...)