curvedarrow: adds curved arrow between two points

In diagram: Functions for Visualising Simple Graphs (Networks), Plotting Flow Diagrams

Description

Connects two points with an ellipsoid line and adds an arrowhead at a certain distance

Usage

curvedarrow(from, to, lwd = 2, lty = 1, lcol = "black", 
            arr.col = lcol, arr.pos = 0.5, curve = 1, dr = 0.01, 
            endhead = FALSE, segment = c(0, 1), ...)

Arguments

from	coordinates (x,y) of the point *from* which to draw arrow.
to	coordinates (x,y) of the point *to* which to draw arrow.
lwd	line width.
lty	line type.
lcol	line color.
arr.col	arrowhead color.
arr.pos	relative position of arrowhead.
curve	relative size of curve (fraction of points distance) - see details.
dr	size of segments, in radians, to draw ellipse (decrease for smoother).
endhead	if TRUE: the arrow line stops at the arrowhead; default = FALSE.
segment	if not c(0,1): then the arrow line will cover only part of the requested path, e.g. if segment = c(0.2,0.8), it will start 0.2 from from and till 0.8.
...	arguments passed to function Arrows.

Details

A curved arrow is drawn between two points '(from, to)'

The position of the arrowhead, is set with arr.pos, a value between 0(start point) and 1(endpoint)

The line curvature is set with curve which expresses the ellipse radius as a fraction of the distance between the two points. For instance, curve=0.5 will draw an ellepse with small radius half of a circle.

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

• "none" : skips the drawing of arrows.

• "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.

The size of the arrow head can be specified with the arguments arr.length and arr.width.

See Arrowhead from package shape for details on arrow head

Value

default

coordinates (x,y) where arrowhead is drawn.

Author(s)

Karline Soetaert <[e-mail]>

See Also

straightarrow, segmentarrow, bentarrow, selfarrow, treearrow, splitarrow,

arrows: the comparable R function,

Arrows: more complicated arrow function from package shape.

Examples

openplotmat(main = "curvedarrow")

pos <- coordinates(pos = 4, my = 0.2)
text(pos, LETTERS[1:4], cex = 2)

for (i in 1:3) 
  curvedarrow(from = pos[1, ] + c(0,-0.05), to = pos[i+1, ] + c(0,-0.05),
              curve = 0.5, arr.pos = 1)
for (i in 1:3) 
  curvedarrow(from = pos[1, ] + c(0, 0.05), to = pos[i+1, ] + c(0, 0.05),
              curve = -0.25, arr.adj = 1, arr.pos = 0.5, 
              arr.type = "triangle", arr.col = "blue")

Example output

Loading required package: shape

diagram documentation built on Oct. 23, 2020, 5:46 p.m.