R: Plot

plotArrows {geosphere} | R Documentation

## 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)

[Package geosphere version 1.5-5 Index]