Arc - Documentation

Usage (signatures)

board.create('arc', [center, p1, p2]);

Draw a circle arc around center through p1. The arc is drawn counter-clockwise from p1 to p2.

Parameters

Name	Type	Description
`center`	PointLike
`p1`	PointLike
`p2`	PointLike

Examples

// Create an arc out of three free points
var p1 = board.create('point', [2.0, 2.0]);
var p2 = board.create('point', [1.0, 0.5]);
var p3 = board.create('point', [3.5, 1.0]);

var a = board.create('arc', [p1, p2, p3]);
board.create('text',[1,6,function(){return 'arclength: '+Math.round(a.Value()*100)/100}])

var t = board.create('transform', [2, 1.5], {type: 'scale'});
var a1 = board.create('arc', [[1, 1], [0, 1], [1, 0]], {strokeColor: 'red'});
var a2 = board.create('curve', [a1, t], {strokeColor: 'red'});

Attributes

Own

anglePoint

Description: Attributes for angle point.
Type: Point
Default Value: {}
Source: options.js, line 4230

center

Description: Attributes for center point.
Type: Point
Default Value: {}
Source: options.js, line 4208

hasInnerPoints

Description

If true, moving the mouse over inner points triggers hasPoint.

Type

Boolean

Default Value

false

See

JXG.GeometryElement#hasPoint

Source

options.js, line 4169

orientation

Description

Orientation of the arc: 'clockwise' or 'counterclockwise' (default).

If the attribute 'selection' is set to 'minor' or 'major' and "the other" arc is to be taken, the orientation of the arc switches, too.

Type

String

Default Value

'counterclockwise'

Example

var p1, p2, p3, a;
p1 = board.create('point', [0, 0]);
p2 = board.create('point', [4, 0]);
p3 = board.create('point', [3, 3]);
board.create('arc', [p1, p2, p3], {
    dash: 3,
    name: 'a',
    withLabel: true,
    strokeColor: 'black',
    strokeWidth: 3,
    orientation: 'clockwise',
    lastArrow: true
});

Source

options.js, line 4117

radiusPoint

Description: Attributes for radius point.
Type: Point
Default Value: {}
Source: options.js, line 4219

selection

Description: Type of arc. Possible values are 'minor', 'major', and 'auto'.
Type: String
Default Value: 'auto'
Source: options.js, line 4107

useDirection

Description

If true, there is a fourth parent point, i.e. the parents are [center, p1, p2, p3]. p1 is still the radius point, p2 the angle point. The arc will be that part of the the circle with center 'center' which starts at p1, ends at the ray between center and p2, and passes p3.

This attribute is immutable (by purpose). This attribute is necessary for circumCircleArcs

Type

Boolean

Default Value

false

Source

options.js, line 4191

useDirection

Description

If true, there is a fourth parent point, i.e. the parents are [center, p1, p2, p3]. p1 is still the radius point, p2 the angle point. The sector will be that part of the the circle with center 'center' which starts at p1, ends at the ray between center and p2, and passes p3.

This attribute is immutable (by purpose). This attribute is necessary for circumCircleSectors

Type

Boolean

Default Value

false

Source

options.js, line 8612

Inherited

none

Members

Own

anglepoint

center

radiuspoint

L

Description

Arc length.

See

Arc#Value

Source

element/arc.js, line 313

anglepoint : JXG.Point

Description: The point defining the arc's angle.
Type: JXG.Point
Source: element/arc.js, line 159

center : JXG.Point

Description: Center of the arc.
Type: JXG.Point
Source: element/arc.js, line 142

radiuspoint : JXG.Point

Description: Point defining the arc's radius.
Type: JXG.Point
Source: element/arc.js, line 150

Inherited

none

Methods

Own

Radius() → {Number}

Determines the arc's current radius. I.e. the distance between Arc#center and Arc#radiuspoint.

Returns

The arc's radius

Type: Number

Details

Source: element/arc.js, line 245

Value(unitopt, radopt) → {Number}

Returns the length of the arc or the value of the angle spanned by the arc.

Parameters

Name Type Attributes Default Description

Name	Type	Attributes	Default	Description
`unit`	String	<optional>	`'length'`	Unit of the returned values. Possible units are 'length' (default): length of the arc line 'radians': angle spanned by the arc in radians 'degrees': angle spanned by the arc in degrees 'semicircle': angle spanned by the arc in radians as a multiple of π, e.g. if the angle is 1.5π, 1.5 will be returned. 'circle': angle spanned by the arc in radians as a multiple of 2π It is sufficient to supply the first three characters of the unit, e.g. 'len'.
`rad`	Number	<optional>		Value of angle which can be used instead of the generic one.

unit

String

'length'

Unit of the returned values. Possible units are

'length' (default): length of the arc line
'radians': angle spanned by the arc in radians
'degrees': angle spanned by the arc in degrees
'semicircle': angle spanned by the arc in radians as a multiple of π, e.g. if the angle is 1.5π, 1.5 will be returned.
'circle': angle spanned by the arc in radians as a multiple of 2π

It is sufficient to supply the first three characters of the unit, e.g. 'len'.

rad

Number

Value of angle which can be used instead of the generic one.

Returns

The arc length or the angle value in various units.

Type: Number

Details

Source: element/arc.js, line 268

getRadius() → {Number}

Returns

Type: Number

Details

Deprecated: Use Arc#Radius
Source: element/arc.js, line 256

hasPointSector(x, y) → {Boolean}

Checks whether (x,y) is within the sector defined by the arc.

Parameters

Name	Type	Description
`x`	Number	Coordinate in x direction, screen coordinates.
`y`	Number	Coordinate in y direction, screen coordinates.

Returns

True if (x,y) is within the sector defined by the arc, False otherwise.

Type: Boolean

Details

Source: element/arc.js, line 371

Inherited

none

Throws

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

Details

Type: JXG.Curve
Source: element/arc.js, line 48