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Turf

Turfjs is a spatial analysis library for JavaScript applications and the turf module contains a Kotlin port of it with support for Kotlin Multiplatform projects.

This module makes use of the classes defined in the geojson module as the GeoJson inputs to many of the turf functions.

The documentation for the ported functions can be found in the API docs, while more details on each function can be found on the Turfjs site.

Installation

Maven Central

dependencies {
  implementation("io.github.elcolto.geokjson:turf:<version>")
}

dependencies {
  implementation "io.github.dellisd.spatialk:turf:<version>"
}

Example

Turf functions are available as top-level functions in Kotlin, or as static member functions in Java.

val point = LngLat(-75.0, 45.0)
val (longitude, latitude) = destination(point, 100.0, 0.0)

Turf Functions

A list of all turf functions and their current status in the port can be found on this page.

Units of Measurement

Units of measurement are represented using the Units enum. These enum values can be passed into functions to specify the units used by other values passed into the function.

val result = convertLength(12.5, from = Units.Kilometers, to = Units.Miles)

Not all units are valid for every function. For example: acres cannot be used as a measure of distance. Calling a function like convertLength with Units.Acres as one of the arguments will cause an IllegalArgumentException.