# bearing: Bearing between geographical locations In argosfilter: Argos locations filter

## Description

Function `bearing` calculates the bearing, in degrees, between two geographical locations. Function `bearingTrack` calculates the bearing between a sequence of locations.

## Usage

 ```1 2``` ```bearing(lat1, lat2, lon1, lon2) bearingTrack(lat, lon) ```

## Arguments

 `lat1` latitude of the first location, in decimal degrees `lat2` latitude of the second location, in decimal degrees `lon1` longitude of the first location, in decimal degrees `lon2` longitude of the second location, in decimal degrees `lat` vector of latitudes, in decimal degrees `lon` vector of longitudes, in decimal degrees

## Details

Bearings are calculated using spherical trigonometry. Formulas are given in Zwillinger (2003).

## Value

`bearing` returns the bearing, in degrees, between the first location and the second location. 0 is North. `bearingTrack` returns a vector of bearings between the sequence of locations.

Carla Freitas

## References

Zwillinger D. (2003) Standard Mathematical Tables and Formulae, 31st edition. Chapman & Hall/CRC, Boca Raton, FL.

`distance`

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11``` ```# Bearing between two geographical locations: lat1<-rnorm(1,80) lat2<-rnorm(1,80) lon1<-rnorm(1,20) lon2<-rnorm(1,20) bearing(lat1,lat2,lon1,lon2) # Bearing between a sequence of 10 geographical locations: lat<-rnorm(10,80) lon<-rnorm(10,20) bearingTrack(lat,lon) ```

### Example output

```[1] -174.5692
[1] -176.381238   25.331500 -155.751354  -27.038854   18.731919    7.303981
[7] -171.209642    5.391068 -173.736972
```

argosfilter documentation built on May 30, 2017, 12:20 a.m.