# earth.poly: Calculating a Minimum Convex Polygon In fossil: Palaeoecological and Palaeogeographical Analysis Tools

## Description

Calculate a minimum convex polygon for a collection of points without knowing what points form the vertices.

## Usage

 `1` ```earth.poly(lats) ```

## Arguments

 `lats` a table with a longitude and latitude column respectively as the first two columns, or a SpatialPoints object with longitude/latitude

## Details

This function will calculate the area of a minimum convex polygon/convex hull for a spherical surface (ie points on a globe).

## Value

The function will return a list consisting of the area in \$km^2\$ (`\\$area`) and a vector with the row numbers of the vertices (`\\$vertices`)

## Author(s)

Matthew Vavrek

`earth.tri`

## Examples

 ```1 2 3``` ```#1/8th the surface area of the earth a <- matrix(c(0, 0, 0, 90, 90, 0, 25, 25), 4, 2, byrow = TRUE) earth.poly(a) ```

### Example output

```Loading required package: sp

Attaching package: 'shapefiles'

The following objects are masked from 'package:foreign':