shape (version 1.1)

Arrows: adds arrows with improved arrowhead to a plot

Description

adds one or more arrows to a plot; arrowhead shape is either curved, a triangle, a circle or simple

Usage

Arrows(x0, y0, x1, y1, code=2, arr.length=0.4, 
    arr.width=arr.length/2, arr.adj=0.5, arr.type="curved", 
    segment=TRUE, lcol="black", lty=1, arr.col=lcol, ...)

Arguments

x0

x-coordinates of points *from* which to draw arrows; either one value or a vector

y0

y-coordinates of points *from* which to draw arrows; either one value or a vector

x1

x-coordinates of points *to* which to draw arrows; either one value or a vector

y1

y-coordinates of points *to* which to draw arrows; either one value or a vector

code

integer code determining kind of arrows to draw

arr.length

approximate length of arrowhead, in cm; either one value or a vector

arr.width

approximate width of arrowhead, in cm; either one value or a vector

arr.adj

0,0.5,1 specifying the adjustment of the arrowhead

arr.type

type of arrowhead to draw, one of "simple","curved","triangle","circle"

segment

logical specifying whether or not to draw line segments

lcol

line color specifications; either one value or a vector

lty

line type specifications; either one value or a vector

arr.col

color of arrowhead; either one value or a vector

...

arguments passed to lines or segments function

Details

x0, y0, x1, y1, arr.length, arr.width, arr.adj, lcol, lty and arr.col can be a vector, of the same length. For each 'i', an arrow is drawn between the point '(x0[i], y0[i])' and the point '(x1[i],y1[i])'. \itemIf 'code=1' an arrowhead is drawn at '(x0[i],y0[i])' \itemif 'code=2' an arrowhead is drawn at '(x1[i],y1[i])'. \itemIf 'code=3' an arrowhead is drawn at both ends of the arrow \itemunless 'arr.length = 0', when no head is drawn. \itemIf arr.adj = 0.5 then the centre of the arrowhead is at the point at which it is drawn. \itemarr.adj = 1 causes the tip of the arrowhead to touch the point. \itemarr.adj = 2 causes the base of the arrowhead to touch the point. The type of the arrowhead is set with "arr.type" which can take the values: \item"simple" : uses comparable R function arrows \item"triangle": uses filled triangle \item"curved" : draws arrowhead with curved edges \item"circle" : draws circular head

See Also

arrows the comparable R function Arrowhead

Examples

xlim <- c(-5 ,5)
  ylim <- c(-10,10)
  plot(0,type="n",xlim=xlim,ylim=ylim,main="Arrows")
  x0<-runif(100,xlim[1],xlim[2])
  y0<-runif(100,ylim[1],ylim[2])
  x1<-x0+runif(100,-1,1)
  y1<-y0+runif(100,-1,1)
  Arrows(x0,y0,x1,y1,arr.length=runif(100),code=2,arr.type="curved",
         arr.col=1:100,lcol=1:100)
  
  plot(0,type="n",xlim=xlim,ylim=ylim,main="Arrows")
  x0<-runif(100,xlim[1],xlim[2])
  y0<-runif(100,ylim[1],ylim[2])
  x1<-x0+runif(100,-1,1)
  y1<-y0+runif(100,-1,1)
  Arrows(x0,y0,x1,y1,arr.length=0.2,code=3,arr.type="circle",
         arr.col="grey")
  
  curve(expr=sin(x),0,2*pi+0.25,main="Arrows")
  x  <- seq(0,2*pi,length.out=10)
  xd <- x+0.025
  Arrows(x,sin(x),xd,sin(xd),type="triangle",arr.length=0.5,segment=FALSE)
  
  xx <- seq(0,10*pi,length.out=1000)
  plot(sin(xx)*xx,cos(xx)*xx,type="l",axes=FALSE,xlab="",ylab="",main="Arrows")
  x  <- seq(0,10*pi,length.out=20)
  x1 <- sin(x)*x
  y1 <- cos(x)*x
  xd <- x+0.01
  x2 <- sin(xd)*xd
  y2 <- cos(xd)*xd
  Arrows(x1,y1,x2,y2,arr.type="curved",arr.length=0.4,segment=FALSE,
         code=1,arr.adj=0.5 )