Point - Documentation

Usage (signatures)

board.create('point', [zopt, x, y]);

Parent elements can be two or three elements of type number, a function which takes no parameter and returns a number, or a string containing a GEONExT constraint.

Every parent element determines one coordinate. If a coordinate is given by a number, the number determines the initial position of a free point. If given by a string or a function that coordinate will be constrained that means the user won't be able to change the point's position directly by mouse because it will be calculated automatically depending on the string or the function's return value.

If two parent elements are given the coordinates will be interpreted as 2D affine Euclidean coordinates, if three such parent elements are given they will be interpreted as homogeneous coordinates.

Parameters

Name	Type	Attributes
`z`	NumberLike	<optional>
`x`	NumberLike
`y`	NumberLike

Examples

Create a free point using (affine) Euclidean coordinates

var p = board.create('point', [3.5, 2.0]);

Create a constrained point using anonymous function

var p1 = board.create('point', [3.5, 2.0]);
var p2 = board.create('point', [3.5, function () { return p1.X(); }]);

board.create('point', [p, t]);

A point can also be created providing a transformation or an array of transformations. The resulting point is a clone of the base point transformed by the given Transformation.

Parameters

Name	Type	Description
`p`	Point	Point
`t`	Transformation \| Array	Transformation or array of transformations

Example

// Create a point using transformations
var trans = board.create('transform', [2, 0.5], {type:'scale'});
var p1 = board.create('point', [3.5, 2.0]);
var p2 = board.create('point', [p1, trans]);

Attributes

Own

attractToGrid

Description

If set to true, the point will only snap to (possibly invisibly) grid points when within Point#attractorDistance of such a grid point.

The coordinates of the grid points are either integer multiples of snapSizeX and snapSizeY (given in user coordinates, not pixels) or are the intersection points of the major ticks of the boards default axes in case that snapSizeX, snapSizeY are negative.

Type

Boolean

Default Value

false

See

Example

board.create('point', [3, 3], { attractToGrid: true, attractorDistance: 10, attractorunit: 'screen' });

Source

options.js, line 8227

attractorDistance

Description: If the distance of the point to one of its attractors is less than this number the point will be a glider on this attracting element. If set to zero nothing happens.
Type: Number
Default Value: 0.0
Source: options.js, line 8181

attractorUnit

Description

Unit for attractorDistance and snatchDistance, used for magnetized points and for snapToPoints. Possible values are 'screen' and 'user'.

Type

String

Default Value

'user'

See

Source

options.js, line 8165

attractors

Description: List of attractor elements. If the distance of the point is less than attractorDistance the point is made to glider of this element.
Type: Array
Default Value: empty
Source: options.js, line 8153

face

Description

There are different point styles which differ in appearance. Posssible values are

Input	Output
cross	x
circle	o
square, []	[]
plus	+
minus	-
divide \|	\|
diamond	<>
diamond2	<> (bigger)
triangleup	^, a, A
triangledown	v
triangleleft	<
triangleright	>

Type

String

Overrides

JXG.Point#face

Default Value

circle

See

JXG.Point#setStyle

Source

options.js, line 8034

ignoredSnapToPoints

Description: List of elements which are ignored by snapToPoints.
Type: Array
Default Value: empty
Source: options.js, line 8312

infoboxDigits

Description

Truncating rule for the digits in the infobox.

'auto': done automatically by JXG.autoDigits()
'none': no truncation
number: truncate after "number digits" with JXG.toFixed()

Type

String | Number

Default Value

'auto'

See

Source

options.js, line 8134

showInfobox

Description

If true, the infobox is shown on mouse/pen over, if false not. If the value is 'inherit', the value of JXG.Board#showInfobox is taken.

Values: true | false | 'inherit'

Type

Boolean | String

Default Value

true

See

JXG.Board#showInfobox

Source

options.js, line 8119

size

Description

Size of a point, either in pixel or user coordinates. Means radius resp. half the width of a point (depending on the face).

Type

Number

Overrides

JXG.Point#size

Default Value

See

Source

options.js, line 8062

sizeUnit

Description

Unit for size. Possible values are 'screen' and 'user.

Type

String

Default Value

'screen'

See

Point#size

Source

options.js, line 8077

snapSizeX

Description

Defines together with Point#snapSizeY the grid the point snaps on to. It is given in user coordinates, not in pixels. The point will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction. If this value is equal to or less than 0, it will use the grid displayed by the major ticks of the default ticks of the default x axes of the board.

Type

Number

Default Value

See

Source

options.js, line 8263

snapSizeY

Description

Defines together with Point#snapSizeX the grid the point snaps on to. It is given in user coordinates, not in pixels. The point will only snap on integer multiples to snapSizeX in x and snapSizeY in y direction. If this value is equal to or less than 0, it will use the grid displayed by the major ticks of the default ticks of the default y axes of the board.

Type

Number

Default Value

See

Source

options.js, line 8281

snapToGrid

Description

If set to true, the point will snap to a grid of integer multiples of Point#snapSizeX and Point#snapSizeY (in user coordinates).

Type

Boolean

Overrides

JXG.Point#snapToGrid

Default Value

false

See

Source

options.js, line 8209

snapToPoints

Description

If set to true, the point will snap to the nearest point in distance of Point#attractorDistance.

Type

Boolean

Overrides

JXG.Point#snapToPoints

Default Value

false

See

Point#attractorDistance

Source

options.js, line 8299

snatchDistance

Description: If the distance of the point to one of its attractors is at least this number the point will be released from being a glider on the attracting element. If set to zero nothing happens.
Type: Number
Default Value: 0.0
Source: options.js, line 8195