network: network.arrow – R documentation

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network.arrow

Add Arrows or Segments to a Plot

Description

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.

Usage

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, ...)

Arguments

`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`

Details

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.

Value

None.

Note

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

Author(s)

Carter T. Butts buttsc@uci.edu

References

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

Examples

#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

v1.16.1

GPL (>= 2)

Authors

Carter T. Butts [aut, cre], David Hunter [ctb], Mark Handcock [ctb], Skye Bender-deMoll [ctb], Jeffrey Horner [ctb], Li Wang [ctb]

Initial release

2020-10-06