@turf/truncate

What is @turf/truncate?

@turf/truncate is a module in the Turf.js library that is used to truncate the precision of coordinates in GeoJSON data. This can be useful for reducing the size of GeoJSON files or for ensuring consistent precision across datasets.

What are @turf/truncate's main functionalities?

Truncate Coordinates

This feature allows you to truncate the coordinates of a GeoJSON object to a specified precision. In this example, the coordinates of a point are truncated to 3 decimal places.

const truncate = require('@turf/truncate');
const point = { "type": "Feature", "geometry": { "type": "Point", "coordinates": [70.123456789, 40.987654321] } };
const truncated = truncate(point, { precision: 3 });
console.log(truncated);

Truncate with Custom Options

This feature allows you to truncate the coordinates of a GeoJSON object with custom options. In this example, the coordinates of a LineString are truncated to 2 decimal places, and the number of coordinates is also limited to 2.

const truncate = require('@turf/truncate');
const lineString = { "type": "Feature", "geometry": { "type": "LineString", "coordinates": [[70.123456789, 40.987654321], [71.123456789, 41.987654321]] } };
const truncated = truncate(lineString, { precision: 2, coordinates: 2 });
console.log(truncated);

Other packages similar to @turf/truncate

geojson-precision

The geojson-precision package allows you to set the precision of GeoJSON coordinates. It is similar to @turf/truncate in that it helps reduce the size of GeoJSON files by limiting the number of decimal places in coordinates. However, it is a standalone package and not part of a larger geospatial library like Turf.js.

simplify-geojson

The simplify-geojson package is used to simplify GeoJSON geometries by reducing the number of points in the geometries. While it does not specifically truncate coordinate precision, it serves a similar purpose of reducing the size and complexity of GeoJSON data. It is more focused on simplifying shapes rather than just truncating coordinates.

README

@turf/truncate

truncate

Takes a GeoJSON Feature or FeatureCollection and truncates the precision of the geometry.

Parameters

• geojson (FeatureCollection | Feature<any>) any GeoJSON Feature, FeatureCollection, Geometry or GeometryCollection.
• precision [number] coordinate decimal precision (optional, default 6)
• coordinates [number] maximum number of coordinates (primarly used to remove z coordinates) (optional, default 3)
• mutate [boolean] allows GeoJSON input to be mutated (significant performance increase if true) (optional, default false)

Examples

var point = turf.point([
    70.46923055566859,
    58.11088890802906,
    1508
]);

var truncated = turf.truncate(point);

//addToMap
var addToMap = [truncated];

Returns (FeatureCollection | Feature<any>) layer with truncated geometry

---

This module is part of the Turfjs project, an open source module collection dedicated to geographic algorithms. It is maintained in the Turfjs/turf repository, where you can create PRs and issues.

Installation

Install this module individually:

$ npm install @turf/truncate

Or install the Turf module that includes it as a function:

$ npm install @turf/turf

Changelog

4.6.0

🚀 New Modules

• @turf/clean-coords Removes redundant coordinates from any GeoJSON Geometry. (PR https://github.com/Turfjs/turf/pull/875 - Author @stebogit)
• @turf/interpolate Takes a set of points and estimates their 'property' values on a grid using the Inverse Distance Weighting (IDW) method.. (PR https://github.com/Turfjs/turf/pull/832 - Author @stebogit)
• @turf/clusters-dbscan Takes a set of Points and partition them into clusters according to DBSCAN's data clustering algorithm. (PR https://github.com/Turfjs/turf/pull/812 and https://github.com/Turfjs/turf/pull/851 - Author @DenisCarriere)

  special mention to this incredibly instructive and fun interactive map by @DenisCarriere 😎👏

• @turf/clusters Provides getCluster, clusterEach, and clusterReduce functions. (PR https://github.com/Turfjs/turf/pull/847 - Author @DenisCarriere)
• @turf/boolean-point-on-line Returns true if a point is on a line. Accepts a optional parameter to ignore the start and end vertices of the linestring. (PR https://github.com/Turfjs/turf/pull/858 - Author @rowanwins)
• @turf/boolean-overlap Takes two features and returns true or false whether or not they overlap, i.e. whether any pair of edges on the two polygons intersect. If there are any edge intersections, the polygons overlap. (PR https://github.com/Turfjs/turf/pull/856 and https://github.com/Turfjs/turf/pull/868 - Author @stebogit @tcql)
• @turf/boolean-equal Determine whether two geometries of the same type have identical X,Y coordinate values. (PR https://github.com/Turfjs/turf/pull/869 - Author @stebogit @tcql)

🏅 New Features/Enhancements

• Sets centered param default to true in @turf/point-grid (PR https://github.com/Turfjs/turf/pull/836 - Contributor @stebogit)
• Adds MultiLineString support for @turf/point-on-line (PR https://github.com/Turfjs/turf/pull/838 - Contributor @stebogit)
• Renames @turf/clusters => @turf/clusters-kmeans, plus adds deprecated warning message to @turf/clusters@4.5.2 (See Issue https://github.com/Turfjs/turf/issues/845)
• Changes output type of @turf/clusters-kmeans (See Issue https://github.com/Turfjs/turf/issues/850 - Contributor @DenisCarriere)
• Adds segmentEach and segmentReduce functions to @turf/meta (See Issue https://github.com/Turfjs/turf/issues/850 - Contributor @DenisCarriere)
• Adds tests and linting on JSDoc in TurfJS core from turf-www; see Issue https://github.com/Turfjs/turf/issues/859 (PR https://github.com/Turfjs/turf/issues/857 + https://github.com/Turfjs/turf/issues/864 + https://github.com/Turfjs/turf/issues/870 - Contributor @DenisCarriere @stebogit)
• Introduces null Geometry support across TurfJS modules (See Issue https://github.com/Turfjs/turf/issues/853) (PR https://github.com/Turfjs/turf/issues/866 - Contributor @DenisCarriere)
• Includes feature(Sub)Index in coordEach/coordReduce (@turf/meta) 🎉 (PR https://github.com/Turfjs/turf/issues/872 - Contributor @DenisCarriere)
• Adds bbox and id params plus geometry method to @turf/helpers (PR https://github.com/Turfjs/turf/issues/877 - Contributor @DenisCarriere)

🐛 Bug Fixes

• Applies @turf/truncate to @turf/line-split splitter input to avoid approximation errors. Fixed #852 (PR https://github.com/Turfjs/turf/pull/855)
• Fixes @turf-mask error (See Issue https://github.com/Turfjs/turf/issues/837) (PR https://github.com/Turfjs/turf/pull/865 - Contributor @thiagoxvo)
• Fixes create-new-module script error on LICENSE file creation (See Issue https://github.com/Turfjs/turf/issues/861) (commit df6986e)
• Fixes @turf/isobands error on commonProperties (See Issue https://github.com/Turfjs/turf/issues/831) (commit 1663f07)