Parabola

Element

A parabola is a special conic section given by one point (the focus) and a line (the directrix).

Usage (signatures)
board.create('parabola', [point, line, startopt, endopt]);

Parent elements are a point and a line or a pair of coordinates. Optional parameters three and four are numbers which define the curve length (e.g. start/end). Default values are -π and π.

Parameters
Name Type Attributes Default Description
point PointLike
line Line
start Number <optional>
-π

parameter of the curve start, default: -π.

end Number <optional>
π

parameter for the curve end, default: π.

Examples

Create a parabola by a point C and a line l

var A = board.create('point', [-1,4]);
var B = board.create('point', [-1,-4]);
var l = board.create('line', [A,B]);
var C = board.create('point', [1,1]);
var el = board.create('parabola',[C,l]);

Create a parabola by a point and a line, both given by coordinate pairs

var par = board.create('parabola',[[3.25, 0], [[0.25, 1],[0.25, 0]]]);

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.Curve
See
Source
element/conic.js, line 592

Extends