R Graphical Manual

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Last data update: 2014.03.03

R: adds a circular, self-pointing arrow to a plot

selfarrow

R Documentation

adds a circular, self-pointing arrow to a plot

Description

adds a circular arrow, from and to the same point

Usage

selfarrow(pos, lwd = 2, lty = 1, lcol = "black", arr.pos = 0.5, 
          path = "L", curve = c(0.1, 0.1), dr = 0.01, code = 1, ...)

Arguments

`pos`	2-valued vector with coordinates (x,y) of points from and to which to draw arrow.
`lwd`	line width.
`lty`	line type.
`lcol`	line color.
`arr.pos`	relative position of arrowhead.
`path`	position of circle: R, L, U, D for right, left, up and down respectively.
`curve`	relative size of curve (fraction of arrow length).
`dr`	size of segments, in radians, to draw ellipse (decrease for smoother).
`code`	how to put the arrowhead.
`...`	arguments passed to function Arrows.

Details

draws a circular arrow from and to one point

The position of the arrowhead on the circle is set with arr.pos, a value between 0 (at start) and 1(at end of circle)

The type of the arrowhead is set with arr.type which can take the values:

"simple" : uses comparable R function arrows.
"triangle": uses filled triangle.
"curved" : draws arrowhead with curved edges.
"circle" : draws circular head.
"ellipse" : draws ellepsoid head
"T" : draws T-shaped (blunt) head

see Arrowhead for details on arrow head.

Value

coordinates (x,y) where arrowhead is drawn

Author(s)

Karline Soetaert <karline.soetaert@nioz.nl>

Examples

openplotmat(main = "selfarrow")

pos <- coordinates(3, mx = 0.05)

text(pos, LETTERS[1:3], cex = 2)

for (i in 1:3) 
  selfarrow(pos = pos[i, ], path = "R", arr.pos = 0.2,
            curve = c(0.05, 0.1), lcol = "darkred")

for (i in 1:3) 
  selfarrow(pos = pos[i, ], path = "L", arr.pos = 0.7,
            lcol = "darkblue", curve = c(0.05, 0.05))

for (i in 1:3) 
  selfarrow(pos = pos[i, ], path = "L", arr.pos = 0.5,
            lcol = "darkgreen", code = i, arr.type = "triangle")