findSegment

描述

¥Description

Finds a particular 2-vertex LineString Segment from a GeoJSON using @turf/meta indexes.

允许使用负索引。Point & MultiPoint will always return null.

¥Negative indexes are permitted. Point & MultiPoint will always return null.

参数

¥Parameters

名称	类型	描述
geojson	FeatureCollection | 特性 | 几何图形	Any GeoJSON Feature or Geometry
options?	对象	可选参数（默认 ）
options.featureIndex?	number	要素索引（默认 0）
options.multiFeatureIndex?	number	多要素索引（默认值为 0）
options.geometryIndex?	number	几何体索引（默认 0）
options.segmentIndex?	number	段索引（默认 0）
options.properties?	对象	Translate Properties to output LineString (default )
options.bbox?	BBox	Translate BBox to output LineString (default )
options.id?	number | string	Translate Id to output LineString (default )

返回

¥Returns

特性<LineString> 2-vertex GeoJSON Feature LineString

¥Feature<LineString> 2-vertex GeoJSON Feature LineString

示例

¥Examples

var multiLine = turf.multiLineString([
  [
    [10, 10],
    [50, 30],
    [30, 40],
  ],
  [
    [-10, -10],
    [-50, -30],
    [-30, -40],
  ],
]);

// First Segment (defaults are 0)
turf.findSegment(multiLine);
// => Feature<LineString<[[10, 10], [50, 30]]>>

// First Segment of 2nd Multi Feature
turf.findSegment(multiLine, { multiFeatureIndex: 1 });
// => Feature<LineString<[[-10, -10], [-50, -30]]>>

// Last Segment of Last Multi Feature
turf.findSegment(multiLine, { multiFeatureIndex: -1, segmentIndex: -1 });
// => Feature<LineString<[[-50, -30], [-30, -40]]>>

安装

¥Installation

$ npm install @turf/meta

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

$ npm install @turf/turf

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