@turf/center-of-mass

What is @turf/center-of-mass?

@turf/center-of-mass is a module from the Turf.js library that calculates the center of mass (centroid) of a given GeoJSON feature. This is particularly useful for geographic data analysis and visualization, where determining the central point of a polygon or multi-polygon is required.

What are @turf/center-of-mass's main functionalities?

Calculate Center of Mass for a Polygon

This feature calculates the center of mass for a given polygon. The code sample demonstrates how to create a polygon and then use the @turf/center-of-mass module to find its centroid.

const turf = require('@turf/turf');

const polygon = turf.polygon([[
  [-70.603637, -33.399918],
  [-70.614624, -33.395332],
  [-70.639343, -33.392466],
  [-70.659942, -33.394759],
  [-70.683975, -33.404504],
  [-70.697021, -33.419406],
  [-70.701141, -33.434306],
  [-70.700454, -33.446339],
  [-70.694274, -33.458369],
  [-70.682601, -33.465816],
  [-70.668869, -33.472117],
  [-70.646209, -33.473835],
  [-70.624923, -33.472117],
  [-70.609817, -33.468107],
  [-70.595397, -33.458369],
  [-70.587158, -33.442901],
  [-70.587158, -33.426283],
  [-70.590591, -33.414248],
  [-70.594711, -33.406224],
  [-70.603637, -33.399918]
]]);

const centerOfMass = turf.centerOfMass(polygon);
console.log(centerOfMass);

Calculate Center of Mass for a MultiPolygon

This feature calculates the center of mass for a given multi-polygon. The code sample demonstrates how to create a multi-polygon and then use the @turf/center-of-mass module to find its centroid.

const turf = require('@turf/turf');

const multiPolygon = turf.multiPolygon([
  [[
    [-73.981149, 40.7681],
    [-73.981149, 40.7681],
    [-73.981149, 40.7681],
    [-73.981149, 40.7681],
    [-73.981149, 40.7681]
  ]],
  [[
    [-73.981149, 40.7681],
    [-73.981149, 40.7681],
    [-73.981149, 40.7681],
    [-73.981149, 40.7681],
    [-73.981149, 40.7681]
  ]]
]);

const centerOfMass = turf.centerOfMass(multiPolygon);
console.log(centerOfMass);

Other packages similar to @turf/center-of-mass

geolib

Geolib is a library to provide basic geospatial operations like distance calculation, bounding boxes, and more. It can calculate the centroid of a set of points, but it does not specifically focus on the center of mass for polygons or multi-polygons like @turf/center-of-mass.

jsts

JSTS is a JavaScript library of spatial predicates and functions for processing geometry. It includes functions for calculating centroids, but it is more complex and offers a broader range of spatial operations compared to the focused functionality of @turf/center-of-mass.

README

@turf/center-of-mass

centerOfMass

Takes a feature or a featureCollection and returns its center of mass using this formula: Centroid of Polygon.

Parameters

• fc (FeatureCollection | Feature) the feature collection or feature

Examples

var feature = {
  "type": "Feature",
  "properties": {},
  "geometry": {
    "type": "Polygon",
    "coordinates": [
      [
        [
          4.854240417480469,
          45.77258200374433
        ],
        [
          4.8445844650268555,
          45.777431068484894
        ],
        [
          4.845442771911621,
          45.778658234059755
        ],
        [
          4.845914840698242,
          45.779376562352425
        ],
        [
          4.846644401550292,
          45.78021460033108
        ],
        [
          4.847245216369629,
          45.78078326178593
        ],
        [
          4.848060607910156,
          45.78138184652523
        ],
        [
          4.8487043380737305,
          45.78186070968964
        ],
        [
          4.849562644958495,
          45.78248921135124
        ],
        [
          4.850893020629883,
          45.78302792142197
        ],
        [
          4.852008819580077,
          45.78374619341895
        ],
        [
          4.852995872497559,
          45.784075398324866
        ],
        [
          4.853854179382324,
          45.78443452873236
        ],
        [
          4.8549699783325195,
          45.78470387501975
        ],
        [
          4.85569953918457,
          45.784793656826345
        ],
        [
          4.857330322265624,
          45.784853511283764
        ],
        [
          4.858231544494629,
          45.78494329284938
        ],
        [
          4.859304428100585,
          45.784883438488365
        ],
        [
          4.858360290527344,
          45.77294120818474
        ],
        [
          4.854240417480469,
          45.77258200374433
        ]
      ]
    ]
  }
};

var centerOfMass = turf.centerOfMass(feature);

//=centerOfMass

Returns Feature<Point> the center of mass

---

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/center-of-mass

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

$ npm install @turf/turf