create an arrow with gradient color

Question

how can I create an arrow or segment with gradient color using R?

Answer 1

I think Jim Lemon should be automagically bestowed 10K, maybe even 20K, rep points on SO just by virtue of all his work over the years creating base-graphics solutions. The guy is amazing. Time and again someone will ask for something on Rhelp, and he will whip up a solution. Here's "random rainbow" courtesy of the help page:

require(plotrix)
x<-c(0,cumsum(rnorm(99)))
 y<-c(0,cumsum(rnorm(99)))
 xydist<-sqrt(x*x+y*y)
 plot(x,y,main="Random walk plot",xlab="X",ylab="Y",type="n")
 color.scale.lines(x,y,c(1,1,0),0,c(0,1,1),colvar=xydist,lwd=2)