PolePoint

Element

This element is used to provide a constructor for the pole point of a line with respect to a conic or a circle. The pole point is the unique reciprocal relationship of a line with respect to a conic. The lines tangent to the intersections of a conic and a line intersect at the pole point of that line with respect to that conic. A line tangent to a conic has the pole point of that line with respect to that conic as the tangent point. See https://en.wikipedia.org/wiki/Pole_and_polar for more information on pole and polar.

Usage (signatures)
board.create('polepoint', [el1, el2]);

Pole point of the line with respect to the conic or the circle.

The order of the parameters does not matter.

Parameters
Name Type Description
el1 Circle | Conic
el2 Line
Examples

Pole point of a line with respect to a conic

var p1 = board.create('point', [-1, 2]);
var p2 = board.create('point', [ 1, 4]);
var p3 = board.create('point', [-1,-2]);
var p4 = board.create('point', [ 0, 0]);
var p5 = board.create('point', [ 4,-2]);
var c1 = board.create('conic',[p1,p2,p3,p4,p5]);

var p6 = board.create('point', [-1, 4]);
var p7 = board.create('point', [2, -2]);
var l1 = board.create('line', [p6, p7]);

var p8 = board.create('polepoint', [c1, l1]);

Pole point of a line with respect to a circle

var p1 = board.create('point', [1, 1]);
var p2 = board.create('point', [2, 3]);
var c1 = board.create('circle',[p1,p2]);

var p3 = board.create('point', [-1, 4]);
var p4 = board.create('point', [4, -1]);
var l1 = board.create('line', [p3, p4]);

var p5 = board.create('polepoint', [c1, l1]);
Attributes

Own

none

Inherited

Members

Own

none

Inherited

Methods

Own

none

Inherited

Events

Own

none

Inherited

Throws

If the element cannot be constructed with the given parent objects an exception is thrown.

Type
Exception

Details

Type
JXG.Point
Source
base/point.js, line 923

Extends