earth.tri {fossil}R Documentation

Calculating the Surface Area Enclosed by Three Geographic Points

Description

Calculate the true area on a sphere enclosed by three points on the earth's surface

Usage

earth.tri(lat1, long1, lat2, long2, lat3, long3)

Arguments

lat1 Latitude of site 1
long1 Longitude of site 1
lat2 Latitude of site 2
long2 Longitude of site 2
lat3 Latitude of site 3
long3 Longitude of site 3

Details

A function to find the area enclosed by three points on the surface of the earth, given their latitudes and longitudes. This function is primarily designed to be a component of earth.poly, which is likely a more useful function for most applications.

Value

Returns a value in kilometers squared of the area enclosed by the three points.

Note

The distance calculated may be up to 0.2% inaccurate, as this function treats the Earth as a sphere with a circumference of 40003 km, rather than an ellipsoid like it actually is.

Author(s)

Matthew Vavrek

References

~put references to the literature/web site here ~

See Also

earth.poly

Examples

##add examples

[Package fossil version 0.2.0 Index]