network.arrow: Add Arrows or Segments to a Plot
In network: Classes for Relational Data

Description Usage Arguments Details Value Note Author(s) References See Also Examples

network.arrow draws a segment or arrow between two pairs of points; unlike arrows or segments, the new plot element is drawn as a polygon.

network.arrow(x0, y0, x1, y1, length = 0.1, angle = 20, 
    width = 0.01, col = 1, border = 1, lty = 1, offset.head = 0,
    offset.tail = 0, arrowhead = TRUE, curve = 0, edge.steps = 50,
    ...)

`x0`	A vector of x coordinates for points of origin
`y0`	A vector of y coordinates for points of origin
`x1`	A vector of x coordinates for destination points
`y1`	A vector of y coordinates for destination points
`length`	Arrowhead length, in current plotting units
`angle`	Arrowhead angle (in degrees)
`width`	Width for arrow body, in current plotting units (can be a vector)
`col`	Arrow body color (can be a vector)
`border`	Arrow border color (can be a vector)
`lty`	Arrow border line type (can be a vector)
`offset.head`	Offset for destination point (can be a vector)
`offset.tail`	Offset for origin point (can be a vector)
`arrowhead`	Boolean; should arrowheads be used? (Can be a vector))
`curve`	Degree of edge curvature (if any), in current plotting units (can be a vector)
`edge.steps`	For curved edges, the number of steps to use in approximating the curve (can be a vector)
`...`	Additional arguments to `polygon`

network.arrow provides a useful extension of segments and arrows when fine control is needed over the resulting display. (The results also look better.) Note that edge curvature is quadratic, with curve providing the maximum horizontal deviation of the edge (left-handed). Head/tail offsets are used to adjust the end/start points of an edge, relative to the baseline coordinates; these are useful for functions like plot.network, which need to draw edges incident to vertices of varying radii.

None.

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

Carter T. Butts buttsc@uci.edu

Butts, C. T. (2008). “network: a Package for Managing Relational Data in R.” Journal of Statistical Software, 24(2). http://www.jstatsoft.org/v24/i02/

plot.network, network.loop, polygon

  #Plot two points
  plot(1:2,1:2)
  
  #Add an edge
  network.arrow(1,1,2,2,width=0.01,col="red",border="black")

network: Classes for Relational Data
Version 1.14-377 created on 2019-03-04.
copyright (c) 2005, Carter T. Butts, University of California-Irvine
                    Mark S. Handcock, University of California -- Los Angeles
                    David R. Hunter, Penn State University
                    Martina Morris, University of Washington
                    Skye Bender-deMoll, University of Washington
 For citation information, type citation("network").
 Type help("network-package") to get started.