R: Intermediate points on a great circle (sphere)

intermediate {geosphere} | R Documentation

## Intermediate points on a great circle (sphere)

### Description

Get intermediate points (way points) between the two locations with longitude/latitude coordinates. gcIntermediate is based on a spherical model of the earth and internally uses `distCosine`.

### Usage

    gcIntermediate(p1, p2, n=50, breakAtDateLine=FALSE, addStartEnd=FALSE, sp=FALSE, sepNA)

### Arguments

`p1` | longitude/latitude of a single point, in degrees. This can be a vector of two numbers, a matrix of 2 columns (first one is longitude, second is latitude) or a SpatialPoints* object
`p2` | as for `p1`
`n` | integer. The desired number of intermediate points
`breakAtDateLine` | logical. Return two matrices if the dateline is crossed?
`addStartEnd` | logical. Add p1 and p2 to the result?
`sp` | logical. Return a SpatialLines object?
`sepNA` | logical. Rather than as a list, return the values as a two column matrix with lines seperated by a row of NA values? (for use in 'plot')

### Value

matrix or list with intermediate points

### Author(s)

Robert Hijmans based on code by Ed Williams (great circle)

### References

http://williams.best.vwh.net/avform.htm#Intermediate

### Examples

    gcIntermediate(c(5,52), c(-120,37), n=6, addStartEnd=TRUE)

[Package geosphere version 1.5-5 Index]