plotArrows {geosphere}

Plot

Description

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

Usage

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

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.

Author(s)

Robert J. Hijmans

Examples

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