spTimer (version 3.3)

spT.geodist: Geodetic/geodesic Distance

Description

This geodetic distance provides the distance between the locations in Kilometers (k.m.) and Miles, using spherical law of Cosines.

Usage

spT.geodist(Lon, Lat, KM = TRUE)
spT.geo.dist(point1, point2)
spT.geo_dist(points)

Arguments

Lon

The longitude position.

Lat

The latitude position.

KM

A logical value, if 'TRUE' then output is in `kilometers', otherwise in `miles'.

point1

In the form of (longitude, latitude) position.

point2

In the form of (longitude, latitude) position.

points

In the form of points 1:(longitude, latitude) 2:(longitude, latitude) positions.

Details

spT.geodist is used to get geodetic distance in both miles and kilometers. spT.geo.dist is only used to get geodetic distance in kilometers with a different format. spT.geo_dist is only used to get geodetic distance in kilometers with a different format.

See Also

NYdata, spT.grid.coords.

Examples

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# Load 28 ozone monitoring locations of New York.
data(NYdata)	
head(NYdata)
NYsite<-unique(NYdata[,1:3])	

# Find the geodetic distance in km
spT.geodist(Lon=NYsite$Longitude, Lat=NYsite$Latitude, KM=TRUE)
   
# Find the geodetic distance in miles
spT.geodist(Lon=NYsite$Longitude, Lat=NYsite$Latitude, KM=FALSE)

##

# using spT.geo.dist
point1<-c(-73.757,42.681)
point2<-c(-73.881,40.866)
spT.geo.dist(point1,point2)

# using spT.geo_dist
points<-c(point1,point2)
spT.geo_dist(points)

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# }
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