flat-projection
==============================================================================
[](https://travis-ci.org/Turbo87/flat-projection-rs)
Fast geodesic distance approximations via flat surface projection
The `FlatProjection` struct can by used to project geographical
coordinates from [WGS84] into a cartesian coordinate system.
In the projected form approximated distance and bearing calculations
can be performed much faster than on a sphere. The precision of these
calculations is very precise for distances up to about 500 km.
[WGS84]: https://en.wikipedia.org/wiki/World_Geodetic_System
Usage
------------------------------------------------------------------------------
```rust
extern crate flat_projection;
use flat_projection::FlatProjection;
fn main() {
let (lon1, lat1) = (6.186389, 50.823194);
let (lon2, lat2) = (6.953333, 51.301389);
let proj = FlatProjection::new(51.05);
let p1 = proj.project(lon1, lat1);
let p2 = proj.project(lon2, lat2);
let distance = p1.distance(&p2);
// -> 75.648 km
}
```
Benchmark
------------------------------------------------------------------------------
```
$ cargo bench
distance/flat time: [22.727 ns 22.955 ns 23.196 ns]
distance/haversine time: [63.349 ns 64.046 ns 64.787 ns]
distance/vincenty time: [358.10 ns 363.16 ns 369.46 ns]
```
According to these results the flat surface approximation is about 3x faster
than the [Haversine] formula.
[Haversine]: https://en.wikipedia.org/wiki/Haversine_formula
Related
------------------------------------------------------------------------------
- [cheap-ruler] – Similar calculations in JavaScripts
- [cheap-ruler-cpp] – C++ port of cheap-ruler
[cheap-ruler]: https://github.com/mapbox/cheap-ruler
[cheap-ruler-cpp]: https://github.com/mapbox/cheap-ruler-cpp
License
-------------------------------------------------------------------------------
This project is released under the [MIT license](LICENSE).