R: Add vertices to a polygon or line

makePoly {geosphere} | R Documentation

## Add vertices to a polygon or line

### Description

Make a polygon or line by adding intermedate points (vertices) on the great circles inbetween the points supplied. This can be relevant when vertices are relatively far apart. It can make the shape of the object to be accurate, when plotted on a plane. `makePoly` will also close the polygon if needed.

### Usage

    makePoly(p, interval=10000, r=6378137, sp=FALSE)
    makeLine(p, interval=10000, r=6378137, sp=FALSE)

### Arguments

`p` | a 2-column matrix (longitude/latitude) or a SpatialPolygons or SpatialLines object
`interval` | maximum interval of points, in units of r
`r` | radius of the earth; default = 6378137
`sp` | Logical. If `TRUE`, a SpatialPolygons object is retunred (depends on the 'sp' package)

### Value

A matrix

### Author(s)

Robert J. Hijmans

### Examples

    pol <- rbind(c(-180,-20), c(-160,5), c(-60, 0), c(-160,-60), c(-180,-20))
    plot(pol)
    lines(pol, col='red', lwd=3)
    pol2 = makePoly(pol, interval=100000)
    lines(pol2, col='blue', lwd=2)

[Package geosphere version 1.5-5 Index]