spatial: Great-circle distance calculations in R

In walterxie/ComMA: Community Matrix Analysis

Description

The functions to calculate the spatial distance (meters) between a large number of longitude and latitude locations.

Usage

deg2rad(deg)

gcd.slc(long1, lat1, long2, lat2)

gcd.hf(long1, lat1, long2, lat2)

gcd.vif(long1, lat1, long2, lat2)

gcd(long1.dg, lat1.dg, long2.dg, lat2.dg, distance = c("slc", "hf", "vif"))

geodesicDist.slc(lati.long.degrees, file = NA, sep = "\t")

geodesicDist.hf(lati.long.degrees, file = NA, sep = "\t")

Arguments

deg	The degrees.
long1, lat1, long2, lat2	radian longitude or latitude of two points.
long1.dg, lat1.dg, long2.dg, lat2.dg	degrees longitude or latitude of two points.
lati.long.degrees	A 2-column data frame contains degrees latitude/longitude coordinates. The 1st col is latitude and 2nd is longitude.
file	Either a character string naming a file or a connection open for writing. "" indicates output to the console. If NA, as default, then do nothing.
sep	The field separator string.

Details

Converts degrees to radians

gcd.slc calculates the geodesic distance (meters) between two points specified by radian latitude/longitude using the spherical Law of Cosines (slc).

gcd.hf calculates the geodesic distance (meters) between two points specified by radian latitude/longitude using the Haversine formula (hf).

gcd.vif calculates the geodesic distance (meters) between two points specified by radian latitude/longitude using Vincenty inverse formula for ellipsoids (vif).

gcd.slc calculates the geodesic distance (meters) between two points specified by degrees latitude/longitude using Haversine formula (hf), Spherical Law of Cosines (slc) and Vincenty inverse formula for ellipsoids (vif).

geodesicDist.slc is a batch processing function to use gcd.slc.

geodesicDist.hf is a batch processing function to use gcd.hf.

Author(s)

Mario Pineda-Krch

Source

http://www.r-bloggers.com/great-circle-distance-calculations-in-r/

Examples

lat1 <- deg2rad(deg)

long1 <- deg2rad(-36.8485)
lat1 <- deg2rad(174.7633)
long2 <- deg2rad(-37.7870)
lat2 <- deg2rad(175.2793)
# Auckland <=> Hamilton
dist.slc <- gcd.slc(long1, lat1, long2, lat2)

dist.hf <- gcd.hf(long1, lat1, long2, lat2)

dist.vif <- gcd.vif(long1, lat1, long2, lat2)

dist.vif <- gcd(-36.8485, 174.7633, -37.7870, 175.2793, distance="vif")

dists.btw <- geodesicDist.slc(env.byplot[, c("Latitude","Longitude")])

dists.btw <- geodesicDist.hf(env.byplot[, c("Latitude","Longitude")])

walterxie/ComMA documentation built on May 3, 2019, 11:51 p.m.