spsurvey (version 3.1)

marinus: Convert Coordinates from Latitude/Longitude to the Equidistant, Cylindric Map Projection

Description

This function converts x,y coordinates measured in units of latitude and longitude, i.e., geographic coordinates measured in decimal degrees, to coordinates in the equidistant, cylindric map projection measured in units of kilometers. The projection center is defined as the midpoint in latitude- longitude space. The map projection is named after Marinus of Tyre.

Usage

marinus(lat, lon)

Arguments

lat

vector of latitudes.

lon

vector of longitudes.

Value

A data frame with column names "x" and "y" containing the x and y coordinates in the equidistant, cylindric map projection measured in units of kilometers.

References

J.P. Snyder. USGS Prof. Paper 1395, p. 90.

Examples

lat <- 45 + runif(100, -5, 5)
lon <- 120 + runif(100, -10, 10)
marinus(lat, lon)