| geodGc {oce} | R Documentation |
Each pair in the longitude and latitude vectors is considered
in turn. For long vectors, this may be slow.
geodGc(longitude, latitude, dmax)
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. |
Data frame of longitude and latitude.
Dan Kelley, based on code from Clark Richards, in turn based on formulae provided by Ed Williams [1].
1. http://williams.best.vwh.net/avform.htm#Intermediate
(link worked for years but failed 2017-01-16).
Other functions relating to geodesy: geodDist,
geodXyInverse, geodXy
## 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)