headlands

headlands is a JavaScript module for creating agricultural headlands from GeoJSON plots. Works in NodeJS and in the browser.

Install

The script is still in beta phase. To install, clone this repo or grab any of the bundled files suitable for your needs from the dist folder.

This module relies on @turf, which you need to include before using this module when running in a browser:

<script src="https://cdn.jsdelivr.net/npm/@turf/turf@5/turf.min.js"></script>

How fast is it?

For an average plot (as per the examples in this repo), creating headlands takes approx. 60-150ms (measured on a MBP early 2015).

Not good, not terrible

When running in a browser, it is advised to run the script inside a web worker in order to avoid unnecessary blocking of the main thread. See the contents of the docs folder for a working example.

Usage

Click here for an online demo

The module exports two methods:

lineString(polygon, { (maxAngle: 30), (minCoordDistance: 10), (debug: false)})

where

polygon a GeoJSON polygon feature

options.maxAngle the maximal allowed turning angle in degrees, defaults to 30 deg

options.minCoordDistance the minimum distance between two coordinates (in meters) used for angle comparison, defaults to 10m.

Example

const headlands = require('headlands')
const fs = require('fs')

let plot = fs.readFileSync('somePlotPolygonFeature.geojson')
let { lineStrings } = headlands.lineString(plot) // contains an array of all potential headlands as GeoJSON linestring features

Returns

An object of the following form:

{
  lineStrings: {
    // a GeoJSON feature collection of lineString features representing each headland
  },
  debug: [
    // an array of GeoJSON points containing debug information (solely for development of this algorithm)
  ]
}

polygons(polygon, { (maxAngle: 30), (minCoordDistance: 10), (width: 12), (debug: false)})

where polygon a GeoJSON polygon feature

options.maxAngle the maximal allowed turning angle in degrees, defaults to 30 deg

options.minCoordDistance the minimum distance between two coordinates (in meters) used for angle comparison, defaults to 10m.

options.width Width of each headland in meters, typically equal to (half) the working width of the sprayer used. Defaults to 12m.

Example

const headlands = require('headlands')
const fs = require('fs')

let plot = fs.readFileSync('somePlotPolygonFeature.geojson')
let { polygons, debug } = headlands.polygons(plot, {width: 15, maxAngle: 40, debug: true}) // contains an array of all potential headlands as GeoJSON polygon features

Returns

An object of the following form:

{
  polygons: {
    // a GeoJSON feature collection of polygon features representing each headland
  },
  debug: [
    // an array of GeoJSON points containing debug information (solely for development of this algorithm)
  ]
}

## License

MIT@Christoph Pahmeyer