network.loop {network}R Documentation

Add Loops to a Plot

Description

network.loop draws a "loop" at a specified location; this is used to designate self-ties in plot.network.

Usage

network.loop(x0, y0, length = 0.1, angle = 10, width = 0.01, 
    col = 1, border = 1, lty = 1, offset = 0, edge.steps = 10, 
    radius = 1, arrowhead = TRUE, xctr=0, yctr=0, ...)

Arguments

x0 a vector of x coordinates for points of origin.
y0 a vector of y coordinates for points of origin.
length arrowhead length, in current plotting units.
angle arrowhead angle (in degrees).
width width for loop body, in current plotting units (can be a vector).
col loop body color (can be a vector).
border loop border color (can be a vector).
lty loop border line type (can be a vector).
offset offset for origin point (can be a vector).
edge.steps number of steps to use in approximating curves.
radius loop radius (can be a vector).
arrowhead boolean; should arrowheads be used? (Can be a vector.)
xctr x coordinate for the central location away from which loops should be oriented.
yctr y coordinate for the central location away from which loops should be oriented.
... additional arguments to polygon.

Details

network.loop is the companion to network.arrow; like the latter, plot elements produced by network.loop are drawn using polygon, and as such are scaled based on the current plotting device. By default, loops are drawn so as to encompass a circular region of radius radius, whose center is offset units from x0,y0 and at maximum distance from xctr,yctr. This is useful for functions like plot.network, which need to draw loops incident to vertices of varying radii.

Value

None.

Note

network.loop is a direct adaptation of gplot.loop, from the sna package.

Author(s)

Carter T. Butts buttsc@uci.edu

See Also

network.arrow, plot.network, polygon

Examples

#Plot a few polygons with loops
plot(0,0,type="n",xlim=c(-2,2),ylim=c(-2,2),asp=1)
network.loop(c(0,0),c(1,-1),col=c(3,2),width=0.05,length=0.4,
  offset=sqrt(2)/4,angle=20,radius=0.5,edge.steps=50,arrowhead=TRUE)
polygon(c(0.25,-0.25,-0.25,0.25,NA,0.25,-0.25,-0.25,0.25), 
    c(1.25,1.25,0.75,0.75,NA,-1.25,-1.25,-0.75,-0.75),col=c(2,3))


[Package network version 1.4-1 Index]