geodGc: Great-circle Segments Between Points on Earth

Description Usage Arguments Value Author(s) References See Also Examples

Description

Each pair in the longitude and latitude vectors is considered in turn. For long vectors, this may be slow.

Usage

1
geodGc(longitude, latitude, dmax)

Arguments

longitude

vector of longitudes, in degrees east

latitude

vector of latitudes, in degrees north

dmax

maximum angular separation to tolerate between sub-segments, in degrees.

Value

Data frame of longitude and latitude.

Author(s)

Dan Kelley, based on code from Clark Richards, in turn based on formulae provided by Ed Williams [1].

References

1. http://williams.best.vwh.net/avform.htm#Intermediate (link worked for years but failed 2017-01-16).

See Also

Other functions relating to geodesy: geodDist, geodXyInverse, geodXy

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
## Not run: 
library(oce)
data(coastlineWorld)
mapPlot(coastlineWorld, type='l',
        longitudelim=c(-80,10), latitudelim=c(35,80),
        projection="+proj=ortho", orientation=c(35, -35, 0))
## Great circle from New York to Paris (Lindberg's flight)
l <- geodGc(c(-73.94,2.35), c(40.67,48.86), 1)
mapLines(l$longitude, l$latitude, col='red', lwd=2)

## End(Not run)


Search within the oce package
Search all R packages, documentation and source code

Questions? Problems? Suggestions? or email at ian@mutexlabs.com.

Please suggest features or report bugs with the GitHub issue tracker.

All documentation is copyright its authors; we didn't write any of that.