lineReduce

Description

Reduce features in any GeoJSON object, similar to Array.reduce().

Parameters

Name	Type	Description
geojson	Geometry | Feature<LineString | Polygon | MultiLineString | MultiPolygon>	object
callback	Function	a method that takes (previousValue, currentLine, featureIndex, multiFeatureIndex, geometryIndex)
initialValue?	*	Value to use as the first argument to the first call of the callback.

Returns

* The value that results from the reduction.

Examples

var multiPoly = turf.multiPolygon([
  turf.polygon([
    [
      [12, 48],
      [2, 41],
      [24, 38],
      [12, 48],
    ],
    [
      [9, 44],
      [13, 41],
      [13, 45],
      [9, 44],
    ],
  ]),
  turf.polygon([
    [
      [5, 5],
      [0, 0],
      [2, 2],
      [4, 4],
      [5, 5],
    ],
  ]),
]);

turf.lineReduce(
  multiPoly,
  function (
    previousValue,
    currentLine,
    featureIndex,
    multiFeatureIndex,
    geometryIndex,
  ) {
    //=previousValue
    //=currentLine
    //=featureIndex
    //=multiFeatureIndex
    //=geometryIndex
    return currentLine;
  },
);

Installation

$ npm install @turf/meta

import { lineReduce } from "@turf/meta";
const result = lineReduce(...);

$ npm install @turf/turf

import * as turf from "@turf/turf";
const result = turf.lineReduce(...);