plotArrows function

Plot

Plot polygons with arrow heads on each line segment, pointing towards the next vertex. This shows the direction of each line segment.

plotArrows(p, fraction=0.9, length=0.15, first='', add=FALSE, ...)

Arguments

• p: Polygons (either a 2 column matrix or data.frame; or a SpatialPolygons* object
• fraction: numeric between 0 and 1. When smaller then 1, interrupted lines are drawn
• length: length of the edges of the arrow head (in inches)
• first: Character to plot on first (and last) vertex
• add: Logical. If TRUE, the plot is added to an existing plot
• ...: Additional arguments, see Details

Author(s)

Robert J. Hijmans

Note

Based on an example in Software for Data Analysis by John Chambers (pp 250-251) but adjusted such that the line segments follow great circles between vertices.

Examples

pol <- rbind(c(-180,-20), c(-160,5), c(-60, 0), c(-160,-60), c(-180,-20))
plotArrows(pol)