oce (version 0.2-1)

geodXy: Convert lat/lon to x/y on earth

Description

Convert lat/lon to x/y on earth

Usage

geodXy(lat, lon, lat.ref, lon.ref, rotate=0)

Arguments

lat

vector of latitudes

lon

vector of longitudes

lat.ref

numeric, reference latitude

lon.ref

numeric, reference longitude

rotate

numeric, counterclockwise angle, in degrees, by which to rotate the (x, y) coordinates about the reference point. This is useful in rotating the coordinate system to align with a coastline, a mean current, etc.

Value

• Data frame of x and y, measured in metres.

Details

This is based on the same geodesic calculations used in geodDist, the documentation of which explains the method and provides literature citations.

See Also

geodDist

Examples

library(oce)
lat <- c(0, 1/60,    0, 1/60)
lon <- c(0,    0, 1/60, 1/60)
plot(geodXy(lat, lon, 0, 0, 0) / 1852)
points(geodXy(lat, lon, 0, 0, 1) / 1852, col='red')