booleans

booleanClockwise

npm install @turf/boolean-clockwise

接收一个 type 为 LineString 的线要素，判断该要素是否顺时针走向

参数

返回

Boolean - true/false

范例

var clockwiseRing = turf.lineString([
  [0, 0],
  [1, 1],
  [1, 0],
  [0, 0]
]);
var counterClockwiseRing = turf.lineString([
  [0, 0],
  [1, 0],
  [1, 1],
  [0, 0]
]);
turf.booleanClockwise(clockwiseRing);
//=true
turf.booleanClockwise(counterClockwiseRing);
//=false

booleanContains

npm install @turf/boolean-contains

接收两个任意类型的要素，判断第二个要素是否包含于第一个要素，即真子集。返回的值与@turf/boolean-within 是完全相反的结果

参数

返回

Boolean - true/false

范例

var line = turf.lineString([
  [1, 1],
  [1, 2],
  [1, 3],
  [1, 4]
]);
var point = turf.point([1, 2]);
turf.booleanContains(line, point);
//=true

booleanCrosses

npm install @turf/boolean-crosses

接收两个任意类型的要素，判断它们是否有相交点

参数

返回

Boolean - true/false

范例

var line1 = turf.lineString([
  [-2, 2],
  [4, 2]
]);
var line2 = turf.lineString([
  [1, 1],
  [1, 2],
  [1, 3],
  [1, 4]
]);
var cross = turf.booleanCrosses(line1, line2);
//=true

booleanDisjoint

npm install @turf/boolean-disjoint

接收两个任意类型的要素，判断它们是否不相交，不相交返回 true

参数

返回

Boolean - true/false

范例

var point = turf.point([2, 2]);
var line = turf.lineString([
  [1, 1],
  [1, 2],
  [1, 3],
  [1, 4]
]);
turf.booleanDisjoint(line, point);
//=true

booleanEqual

npm install @turf/boolean-equal

接收两个任意类型的要素，判断它们的坐标是否相等

值得注意的是，坐标的顺序没有影响，只要全部坐标对的对应相等，就认为是相等的坐标

参数

返回

Boolean - true/false

范例

var pt1 = turf.point([0, 0]);
var pt2 = turf.point([0, 0]);
var pt3 = turf.point([1, 1]);
turf.booleanEqual(pt1, pt2);
//= true
turf.booleanEqual(pt2, pt3);
//= false
var pt1 = turf.polygon([
  [
    [114.11207138646921, 40.065237806396226],
    [116.72681748022632, 37.74008299506812],
    [117.2981065427258, 40.28349411053313],
    [114.11207138646921, 40.065237806396226]
  ]
]);
var pt2 = turf.polygon([
  [
    [117.2981065427258, 40.28349411053313],
    [116.72681748022632, 37.74008299506812],
    [114.11207138646921, 40.065237806396226],
    [117.2981065427258, 40.28349411053313]
  ]
]);
var boolean = turf.booleanEqual(pt1, pt2); // true，坐标顺序不影响

booleanOverlap

npm install @turf/boolean-overlap

接收两个任意类型的要素，判断它们是否有交集重叠

值得注意的是，判断的要素必须是同类型的：面要素和面要素、线和线、MultiPoint 和 MultiPoint、MultiLineString 和 MultiLineString、MultiPolygon 和 MultiPolygon

参数

返回

Boolean - true/false

范例

var poly1 = turf.polygon([
  [
    [0, 0],
    [0, 5],
    [5, 5],
    [5, 0],
    [0, 0]
  ]
]);
var poly2 = turf.polygon([
  [
    [1, 1],
    [1, 6],
    [6, 6],
    [6, 1],
    [1, 1]
  ]
]);
var poly3 = turf.polygon([
  [
    [10, 10],
    [10, 15],
    [15, 15],
    [15, 10],
    [10, 10]
  ]
]);
turf.booleanOverlap(poly1, poly2);
//=true
turf.booleanOverlap(poly2, poly3);
//=false

booleanParallel

npm install @turf/boolean-parallel

接收两个线要素，判断它们是否平行

参数

返回

Boolean - true/false

范例

var line1 = turf.lineString([
  [0, 0],
  [0, 1]
]);
var line2 = turf.lineString([
  [1, 0],
  [1, 1]
]);
turf.booleanParallel(line1, line2);
//=true

booleanPointInPolygon

npm install @turf/boolean-point-in-polygon

接收一个点要素和一个面要素，判断点要素是否在面要素内

参数

options

返回

Boolean - true/false

范例

var pt = turf.point([-72, 41]);
var poly = turf.polygon([
  [
    [-81, 41],
    [-81, 47],
    [-72, 47],
    [-72, 41],
    [-81, 41]
  ]
]);
var boolean = turf.booleanPointInPolygon(pt, poly, {
  ignoreBoundary: false
});
//= true
var boolean2 = turf.booleanPointInPolygon(pt, poly, {
  ignoreBoundary: true
});
//= false 忽略边界，点不在面要素内

booleanPointOnLine

npm install @turf/boolean-point-on-line

接收一个点要素和一个线要素，判断点要素是否在线要素上

参数

options

返回

Boolean - true/false

范例

var pt = turf.point([0, 0]);
var line = turf.lineString([
  [-1, -1],
  [1, 1],
  [1.5, 2.2]
]);
var isPointOnLine = turf.booleanPointOnLine(pt, line);
//=true
var pt = turf.point([-1, -1]);
var line = turf.lineString([
  [-1, -1],
  [1, 1],
  [1.5, 2.2]
]);
var isPointOnLine = turf.booleanPointOnLine(pt, line, {
  ignoreEndVertices: true
});
//=false

booleanWithin

npm install @turf/boolean-within

接收两个任意类型的要素，判断第一个要素是否包含于第二个要素，即真子集。返回的值与@turf/boolean-contains 是完全相反的结果

参数

返回

Boolean - true/false

范例

var line = turf.lineString([
  [1, 1],
  [1, 2],
  [1, 3],
  [1, 4]
]);
var point = turf.point([1, 2]);
turf.booleanWithin(point, line);
//=true