## Overview

The `nvctr`

package implements the n-vector approach to geographical position calculations using an ellipsoidal model of Earth as described in (Gade 2010).

Implementations in various computer languages can be found at the n-vector page (Navigation Group 2010).

## Installation

You can install the development version of `nvctr`

from GitHub with:

`devtools::install_github("euctrl-pru/nvctr")`

or the CRAN version (when this package will land to CRAN):

`install.packages("nvctr")`

## Usage

`nvctr`

can be used to solve geographical position calculation like (example numbers refer to the ones in the vignette):

- Calculate the surface distance between two geographical positions (Example 5).
- Find the destination point given start point, azimuth/bearing and distance (Example 8).
- Find the mean position (center/midpoint) of several geographical positions (Example 6).
- Find the intersection between two paths (Example 9).
- Find the cross track distance between a path and a position (Example 10).

## References

Gade, Kenneth. 2010. “A Non-Singular Horizontal Position Representation.” *Journal of Navigation*. https://doi.org/10.1017/S0373463309990415.