plotArrows: Plot

In geosphere: Spherical Trigonometry

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)

Example output

geosphere documentation built on May 2, 2019, 5:16 p.m.