geopath {plotKML} | R Documentation |

Derives a SpatialLines class object showing the shortest path between the two geographic locations and based on the Haversine Formula for Great Circle distance.

geopath(lon1, lon2, lat1, lat2, ID, n.points, print.geo = FALSE)

`lon1` |
longitude coordinate of the first point |

`lon2` |
longitude coordinate of the second point |

`lat1` |
latitude coordinate of the first point |

`lat2` |
latitude coordinate of the second point |

`ID` |
(optional) point ID character |

`n.points` |
number of intermediate points |

`print.geo` |
prints the distance and bearing |

Number of points between the start and end point is derived using a simple formula:

`round(sqrt(distc)/sqrt(2), 0)`

where `distc`

is the Great Circle Distance.

Bearing is expressed in degrees from north. Distance is expressed in kilometers (Great Circle Distance).

Tomislav Hengl

fossil package (http://CRAN.R-project.org/package=fossil)

Haversine formula from Math Forums (http://mathforum.org/dr.math/)

`kml_layer.SpatialLines`

, `kml_layer.STTDF`

, `fossil::earth.bear`

library(fossil) ams.ny <- geopath(lon1=4.892222, lon2=-74.005973, lat1=52.373056, lat2=40.714353, print.geo=TRUE) # write to a file: kml(ams.ny)

[Package *plotKML* version 0.5-6 Index]