Aladin Lite API documentation

A

Description:

Aladin Lite API namespace for creating celestial objects.

Source:

A.js, line 60

Example

// Usage example:
import { A } from 'aladin-lite';

const aladin = new A.aladin("#aladin-lite-div", { survey: 'your survey url', fov: 180, projection: 'SIN' });

Methods

(static) HiPS(id, optionsopt) → {HiPS}

Description:

Creates a HiPS image object

Source:

A.js, line 109

Parameters:

Name	Type	Attributes	Description
`id`	string		Can be: An http url towards a HiPS. A relative path to your HiPS A special ID pointing towards a HiPS. One can found the list of IDs here
`options`	HiPSOptions	<optional>	Options describing the survey

Returns:

- A HiPS image object

Type: HiPS

(static) MOCFromCone(circle, optionsopt, successCallbackopt, errorCallbackopt) → {MOC}

Description:

Creates a new MOC (Multi-Order-Coverage) from an object describing a cone on the sky

Source:

A.js, line 476

Parameters:

Name Type Attributes Description

circle

Object

A object describing a cone in the sky

Properties

Name	Type	Description
`ra`	number	Right-ascension of the circle's center (in deg)
`dec`	number	Declination of the circle's center (in deg)
`radius`	number	Radius of the circle (in deg)

options MOCOptions <optional> Display options for the MOC

successCallback function <optional> Callback function when the MOC loads

errorCallback function <optional> Callback function when the MOC fails loading

Returns:

Returns a new MOC object

Type: MOC

(static) MOCFromJSON(jsonMOC, optionsopt, successCallbackopt, errorCallbackopt) → {MOC}

Description:

Creates a new MOC (Multi-Order-Coverage) from a JSON-like dictionary (javascript Object)

Source:

A.js, line 441

Example

var json = {
  "3": [517],
  "4": [2065,2066,2067,2112,2344,2346,2432],
  "5": [8221,8257,8258,8259,8293,8304,8305,8307,8308,8452,8456,9346,9352,9354,9736],
  "6": [32861,32862,32863,32881,32882,32883,32892,32893,33025,33026,33027,33157,33168,33169,33171,
  33181,33224,33225,33227,33236,33240,33812,33816,33828,33832,37377,37378,37379,37382,37388,
  37390,37412,37414,37420,37422,37562,38928,38930,38936,38948,38952],
  "7": [131423,131439,131443,131523,131556,131557,131580,131581,132099,132612,132613,132624,132625,132627,132637,
  132680,132681,132683,132709,132720,132721,132904,132905,132948,132952,132964,132968,133008,133009,133012,135252,135256,135268,135316,135320,135332,135336,148143,148152,148154,149507,149520
  ,149522,149523,149652,149654,149660,149662,149684,149686,149692,149694,149695,150120,150122,150208,150210,150216,150218,150240,150242,150243,155748,155752,155796,155800,155812,155816]
};
var moc = A.MOCFromJSON(json, {opacity: 0.25, color: 'magenta', lineWidth: 3});
aladin.addMOC(moc);

Parameters:

Name	Type	Attributes	Description
`jsonMOC`	Object		The MOC stores as a JSON-like dictionary
`options`	MOCOptions	<optional>	Display options for the MOC
`successCallback`	function	<optional>	Callback function when the MOC loads
`errorCallback`	function	<optional>	Callback function when the MOC fails loading

Returns:

Returns a new MOC object

Type: MOC

(static) MOCFromPolygon(polygon, optionsopt, successCallbackopt, errorCallbackopt) → {MOC}

Description:

Creates a new MOC (Multi-Order-Coverage) from an object describing a polygon on the sky

Source:

A.js, line 499

Parameters:

Name Type Attributes Description

polygon

Object

A object describing a polygon in the sky

Properties

Name	Type	Description
`ra`	Array.<number>	Right-ascensions of the polygon's vertices (in deg)
`dec`	Array.<number>	Declination of the polygon's vertices (in deg)

options MOCOptions <optional> Display options for the MOC

successCallback function <optional> Callback function when the MOC loads

errorCallback function <optional> Callback function when the MOC fails loading

Returns:

Returns a new MOC object

Type: MOC

(static) MOCFromURL(url, optionsopt, successCallbackopt, errorCallbackopt) → {MOC}

Description:

Creates a new MOC (Multi-Order-Coverage) from an url

Source:

A.js, line 421

Parameters:

Name	Type	Attributes	Description
`url`	string		The url to the MOC (e.g. stored as FITS file)
`options`	MOCOptions	<optional>	Display options for the MOC
`successCallback`	function	<optional>	Callback function when the MOC loads
`errorCallback`	function	<optional>	Callback function when the MOC fails loading

Returns:

Returns a new MOC object

Type: MOC

(static) Utils() → {AladinUtils}

Description:

Returns Utils object. This contains utilitary methods such as HEALPix basic or projection methods.

Source:

A.js, line 995

Returns:

Returns a new box window object.

Type: AladinUtils

(static) aladin(divSelector, optionsopt) → {Aladin}

Description:

Creates an Aladin Lite instance within the specified HTML element.

Source:

A.js, line 76

Example

var aladin;
 A.init.then(() => {
     aladin = A.aladin('#aladin-lite-div', {fullScreen: true, cooFrame: "ICRSd", showSimbadPointerControl: true, showShareControl: true, showShareControl: true, survey: 'https://alasky.cds.unistra.fr/DSS/DSSColor/', fov: 180, showContextMenu: true});
 })

Parameters:

Name	Type	Attributes	Description
`divSelector`	string \| HTMLElement		The ID selector for the HTML element or the HTML element itself
`options`	AladinOptions	<optional>	Options for configuring the Aladin Lite instance.

Returns:

An instance of the Aladin Lite library.

Type: Aladin

(static) box(options) → {Box}

Description:

Creates a box user interface for Aladin Lite.

Source:

A.js, line 963

Example

let box = A.box({
      header: {
          title: "My window",
          draggable: true,
      },
      // Adding a CSS class allowing you to position your window on the aladin lite view
      classList: ['myBox'],
      content: "This is the content of my window<br/> I can write proper html",
  })
  aladin.addUI(box)

Parameters:

Name Type Description

options

Object

Options for configuring the button.

Properties

Name Type Attributes Description

header

Object

The header of the box

Properties

Name	Type	Attributes	Default	Description
`draggable`	boolean	<optional>	`false`	Can move the window by dragging its title.
`title`	string	<optional>		A title name for the window

content HTMLElement | string | Widget <optional> The content to be added to the button.

cssStyle CSSStyleSheet <optional> The CSS styles to apply to the button.

position Object | string <optional> The position of the button.

Returns:

Returns a new box window object.

Type: Box

(static) button(options) → {ActionButton}

Description:

Creates a user interface button for Aladin Lite

Source:

A.js, line 866

Example

<!-- This example instanciates a customized button that when clicked, enters the user in
the polygonal selection mode. Once the polygon selection is done, the vertices are converted
to sky coords and a Multi-Order Coverage (MOC) is created from that list of sky coords. -->
<!doctype html>
<html>
<head>
</head>
<body>


<div id="aladin-lite-div" style="width: 512px; height: 512px"></div>

<script type="module">
    import A from aladin-lite;
    let aladin;
    A.init.then(() => {
        var aladin = A.aladin(
            '#aladin-lite-div',
            {
                survey: 'P/allWISE/color', // set initial image survey
                projection: 'AIT', // set a projection
                fov: 1.5, // initial field of view in degrees
                target: 'NGC 2175', // initial target
                cooFrame: 'icrs', // set galactic frame
                reticleColor: '#ff89ff', // change reticle color
                reticleSize: 64, // change reticle size
                showContextMenu: true,
            }
        );

        let btn = A.button({
            content: 'My button',
            classList: ['myButton'],
            tooltip: {cssStyle: {color: 'red'}, content: 'Create a moc in pink!', position: {direction: 'top'}},
            action(o) {
                aladin.select('poly', p => {
                    try {
                        let ra = []
                        let dec = []
                        for (const v of p.vertices) {
                            let [lon, lat] = aladin.pix2world(v.x, v.y);
                            ra.push(lon)
                            dec.push(lat)
                        }

                        let moc = A.MOCFromPolygon(
                            {ra, dec},
                            {name: 'poly', lineWidth: 3.0, color: 'pink'},
                        );
                        aladin.addMOC(moc)
                    } catch(_) {
                        alert('Selection covers a region out of the projection definition domain.');
                    }
                })
            }
        });

        aladin.addUI(btn)
    });
</script>
<style>
    .myButton {
        position: absolute;
        bottom: 0;
        left: 0;

        background-color: pink;
    }
</style>
</body>
</html>

Parameters:

Name Type Description

options

Object

Options for configuring the button.

Properties

Name	Type	Attributes	Default	Description
`toggled`	boolean	<optional>	`false`	Whether the button is initially toggled.
`action`	function	<optional>		The callback function to execute when the button is clicked.
`title`	string	<optional>		The title attribute for the button.
`icon`	Object	<optional>		An icon object for the button.
`disable`	boolean	<optional>	`false`	Whether the button is initially disabled.
`content`	HTMLElement \| string \| Widget	<optional>		The content to be added to the button.
`cssStyle`	CSSStyleSheet	<optional>		The CSS styles to apply to the button.
`tooltip`	Object	<optional>		A tooltip.
`position`	Object \| string	<optional>		The position of the button.
`size`	string	<optional>		The size of the button. Can be 'medium' or 'small'

Returns:

Returns a new button object representing the graphic overlay.

Type: ActionButton

(static) catalog(options) → {Catalog}

Description:

Represents a catalog with configurable options for display and interaction.

Source:

A.js, line 521

Parameters:

Name	Type	Description
`options`	CatalogOptions	Configuration options for the catalog.

Returns:

Type: Catalog

(static) catalogFromNED(target, radius, optionsopt, successCallbackopt, errorCallbackopt) → {Catalog}

Description:

Create a catalog from a NED cone search query

Source:

A.js, line 735

Example

A.catalogFromNED('09 55 52.4 +69 40 47', 0.1, {onClick: 'showPopup', shape: 'plus'})

Parameters:

Name Type Attributes Description

target

string | Object

can be either a string representing a position or an object name, or can be an object with keys 'ra' and 'dec' (values being in decimal degrees)

Properties

Name	Type	Description
`ra`	number	Right Ascenscion in degrees of the cone's center
`dec`	number	Declination in degrees of the cone's center

radius number Radius of the cone in degrees

options CatalogOptions <optional> Additional configuration options for the catalogue.

successCallback function <optional> The callback function to execute on successful catalog creation.

errorCallback function <optional> The callback function to execute on error during catalog creation.

Returns:

Type: Catalog

(static) catalogFromSKAORucio(target, radiusDegrees, optionsopt, successCallbackopt, errorCallbackopt) → {Catalog}

Description:

Create a catalog from a SKAORucio cone search query

Source:

A.js, line 780

Example

A.catalogFromSKAORucio('09 55 52.4 +69 40 47', 0.1, {onClick: 'showPopup', shape: 'plus'})

Parameters:

Name Type Attributes Description

target

string | Object

can be either a string representing a position or an object name, or can be an object with keys 'ra' and 'dec' (values being in decimal degrees)

Properties

Name	Type	Description
`ra`	number	Right Ascenscion in degrees of the cone's center
`dec`	number	Declination in degrees of the cone's center

radiusDegrees number Radius of the cone in degrees

options CatalogOptions <optional> Additional configuration options for the catalogue.

successCallback function <optional> The callback function to execute on successful catalog creation.

errorCallback function <optional> The callback function to execute on error during catalog creation.

Returns:

Type: Catalog

(static) catalogFromSimbad(target, radius, optionsopt, successCallbackopt, errorCallbackopt) → {Catalog}

Description:

Create a catalog from a SIMBAD cone search query

Source:

A.js, line 641

Example

A.catalogFromSimbad('09 55 52.4 +69 40 47', 0.1, {onClick: 'showTable', limit: 1000}, (cat) => {
     aladin.addCatalog(cat)
 });

Parameters:

Name Type Attributes Description

target

string | Object

can be either a string representing a position or an object name, or can be an object with keys 'ra' and 'dec' (values being in decimal degrees)

Properties

Name	Type	Description
`ra`	number	Right Ascenscion in degrees of the cone's center
`dec`	number	Declination in degrees of the cone's center

radius number Radius of the cone in degrees

options

Object | CatalogOptions

Additional configuration options for SIMBAD cone search. See the SIMBAD cone search parameters.

Properties

Name	Type	Attributes	Default	Description
`limit`	number	<optional>		The max number of sources to return
`orderBy`	string	<optional>	`'nb_ref'`	Order the result by specific ref number
`verbosity`	number	<optional>	`2`	Verbosity, put 3 if you want all the column

successCallback function <optional> The callback function to execute on successful catalog creation.

errorCallback function <optional> The callback function to execute on error during catalog creation.

Returns:

A new instance of the Catalog class created from the SIMBAD cone search.

Type: Catalog

(static) catalogFromSkyBot(ra, dec, radius, epoch, queryOptions, optionsopt, successCallbackopt, errorCallbackopt) → {Catalog}

Description:

Create a catalog from a SkyBot cone search query

Source:

A.js, line 840

Parameters:

Name	Type	Attributes	Description
`ra`	number		Right Ascenscion in degrees of the cone's center
`dec`	number		Declination in degrees of the cone's center
`radius`	number		Radius of the cone in degrees
`epoch`	string		Requested epoch, expressed in Julian day or ISO dateTime
`queryOptions`	Object		options passed to SkyBot, see https://vo.imcce.fr/webservices/skybot/?conesearch
`options`	CatalogOptions	<optional>	Additional configuration options for the catalogue.
`successCallback`	function	<optional>	The callback function to execute on successful catalog creation.
`errorCallback`	function	<optional>	The callback function to execute on error during catalog creation.

Returns:

Type: Catalog

(static) catalogFromURL(url, optionsopt, successCallbackopt, errorCallbackopt, useProxyopt) → {Catalog}

Description:

Asynchronously creates a new catalog instance from the specified URL with additional options.

Source:

A.js, line 534

Example

// Create a catalog from a URL using the A.catalogFromURL method
const catalogURL = "https://example.com/catalog";
const catalogOptions = {
  name: "My Catalog",
  color: "#ff0000",
  sourceSize: 10,
  // ... other options
};

const myCatalog = A.catalogFromURL(
  catalogURL,
  catalogOptions,
  (catalog) => {
    // Catalog successfully loaded
    aladin.addCatalog(catalog)
  },
  (error) => {
    // Error loading catalog
    console.error("Error loading catalog:", error);
  },
);

Parameters:

Name	Type	Attributes	Default	Description
`url`	string			The URL of the catalog.
`options`	CatalogOptions	<optional>		Additional configuration options for the catalog.
`successCallback`	function	<optional>		The callback function to execute on successful catalog creation.
`errorCallback`	function	<optional>		The callback function to execute on error during catalog creation.
`useProxy`	boolean	<optional>	`false`	Indicates whether to use a proxy for loading the catalog.

Returns:

A new instance of the Catalog class created from the specified URL.

Type: Catalog

(static) catalogFromVizieR(vizCatId, target, radius, optionsopt, successCallbackopt, errorCallbackopt) → {Catalog}

Description:

Create a catalog from a SKAORucio cone search query

Source:

A.js, line 809

Example

const cat = A.catalogFromVizieR('I/311/hip2', 'M 45', 5, {onClick: 'showTable'});
     const cat2 = A.catalogFromVizieR('I/311/hip2', '12 +9', 5, {onClick: 'showTable'});

Parameters:

Name Type Attributes Description

vizCatId string the id of the ViZieR catalog

target

string | Object

can be either a string representing a position or an object name, or can be an object with keys 'ra' and 'dec' (values being in decimal degrees)

Properties

Name	Type	Description
`ra`	number	Right Ascenscion in degrees of the cone's center
`dec`	number	Declination in degrees of the cone's center

radius number Radius of the cone in degrees

options CatalogOptions <optional> Additional configuration options for the catalogue.

successCallback function <optional> The callback function to execute on successful catalog creation.

errorCallback function <optional> The callback function to execute on error during catalog creation.

Returns:

Type: Catalog

(static) catalogHiPS(url, options) → {ProgressiveCat}

Description:

Creates progressive catalog object (i.e. Simbad/Gaia)

Source:

A.js, line 353

Example

let gaia = A.catalogHiPS('http://axel.u-strasbg.fr/HiPSCatService/I/345/gaia2', {onClick: 'showTable', color: 'orange', name: 'Gaia', filter: myFilterFunction});
aladin.addCatalog(gaia)

Parameters:

Name	Type	Description
`url`	string	Root url of the catalog
`options`	CatalogOptions	Options for configuring the catalogue.

Returns:

Returns a new Overlay object representing the graphic overlay.

Type: ProgressiveCat

(static) circle(ra, dec, radiusDeg, options) → {Circle}

Description:

Creates a circle shape

Source:

A.js, line 273

Parameters:

Name	Type	Description
`ra`	number	Right Ascension (RA) coordinate of the center in degrees.
`dec`	number	Declination (Dec) coordinate of the center in degrees.
`radiusDeg`	number	Radius in degrees.
`options`	ShapeOptions	Options for configuring the circle.

Returns:

Type: Circle

(static) coo(longitude, latitude, prec) → {Coo}

Description:

Creates a new coo from a longitude and latitude given in degrees

Source:

A.js, line 372

Parameters:

Name	Type	Description
`longitude`	number	longitude (decimal degrees)
`latitude`	number	latitude (decimal degrees)
`prec`	number	precision (8: 1/1000th sec, 7: 1/100th sec, 6: 1/10th sec, 5: sec, 4: 1/10th min, 3: min, 2: 1/10th deg, 1: deg

Returns:

Returns a new Coo object

Type: Coo

(static) ellipse(ra, dec, radiusRaDeg, radiusDecDeg, rotationDeg, options) → {Ellipse}

Description:

Creates an ellipse shape

Source:

A.js, line 291

Parameters:

Name	Type	Description
`ra`	number	Right Ascension (RA) coordinate of the center in degrees.
`dec`	number	Declination (Dec) coordinate of the center in degrees.
`radiusRaDeg`	number	the radius along the ra axis in degrees
`radiusDecDeg`	number	the radius along the dec axis in degrees
`rotationDeg`	number	the rotation angle in degrees
`options`	ShapeOptions	Options for configuring the ellipse.

Returns:

Type: Ellipse

(static) footprint(shapes, sourceopt) → {Footprint}

Description:

Creates a new footprint from an array of polygons and optionally a source

Source:

A.js, line 389

Parameters:

Name	Type	Attributes	Description
`shapes`	Array.<Circle> \| Array.<Polyline> \| Array.<Ellipse> \| Array.<Vector>		an array of A.polygon objects
`source`	Source	<optional>	a A.source object associated with the footprint

Returns:

Returns a new Footprint object

Type: Footprint

(static) footprintsFromSTCS(stcs, optionsopt) → {Array.<(Polyline|Circle)>}

Description:

Parse shapes from a STC-S string

Source:

A.js, line 405

Parameters:

Name	Type	Attributes	Description
`stcs`	string		The STC-S string describing the shapes
`options`	ShapeOptions	<optional>	Options for the shape

Returns:

Returns a list of shapes from the STC-S string

Type: Array.<(Polyline|Circle)>

(static) graphicOverlay(options) → {Overlay}

Description:

Creates a graphic overlay on the Aladin Lite view.

Source:

A.js, line 333

Example

var overlay = A.graphicOverlay({ color: '#ee2345', lineWidth: 3, lineDash: [2, 4]});

Parameters:

Name Type Description

options

Object

Options for configuring the graphic overlay.

Properties

Name	Type	Attributes	Description
`color`	string	<optional>	The color of the graphic overlay.
`lineWidth`	number	<optional>	The width of the lines in the graphic overlay.
`lineDash`	Array	<optional>	The dash pattern for the lines in the graphic overlay.

Returns:

Returns a new Overlay object representing the graphic overlay.

Type: Overlay

(static) image(url, optionsopt) → {Image}

Description:

Creates a celestial source object with the given coordinates.

Source:

A.js, line 144

Example

aladin.setOverlayImageLayer(A.image(
      "https://nova.astrometry.net/image/25038473?filename=M61.jpg",
      {
          name: "M61",
          imgFormat: 'jpeg',
          wcs: {
              NAXIS: 0, // Minimal header
              CTYPE1: 'RA---TAN', // TAN (gnomic) projection
              CTYPE2: 'DEC--TAN', // TAN (gnomic) projection
              EQUINOX: 2000.0, // Equatorial coordinates definition (yr)
              LONPOLE: 180.0, // no comment
              LATPOLE: 0.0, // no comment
              CRVAL1: 185.445488837, // RA of reference point
              CRVAL2: 4.47896032431, // DEC of reference point
              CRPIX1: 588.995094299, // X reference pixel
              CRPIX2: 308.307905197, // Y reference pixel
              CUNIT1: 'deg', // X pixel scale units
              CUNIT2: 'deg', // Y pixel scale units
              CD1_1: -0.000223666022989, // Transformation matrix
              CD1_2: 0.000296578064584, // no comment
              CD2_1: -0.000296427555509, // no comment
              CD2_2: -0.000223774308964, // no comment
              NAXIS1: 1080, // Image width, in pixels.
              NAXIS2: 705 // Image height, in pixels.
          },
          successCallback: (ra, dec, fov, image) => {
              aladin.gotoRaDec(ra, dec);
              aladin.setFoV(fov * 5)
          }
      },
  ));

Parameters:

Name	Type	Attributes	Description
`url`	string		Options describing the fits file. An url is mandatory
`options`	ImageOptions	<optional>	Options describing the fits file. An url is mandatory

Returns:

- A HiPS image object

Type: Image

(static) imageHiPS()

Source:

A.js, line 135

Deprecated:

Old method name, use A.HiPS instead.

(async, static) init() → {Promise.<void>}

Description:

Initializes the Aladin Lite library, checking for WebGL2 support. This method must be called before instancing an Aladin Lite object.

Source:

A.js, line 1008

Example

// Usage example:
A.init
  .then(async () => {
    const aladinInstance = A.aladin('div', requestedOptions);
    // Perform further actions with the Aladin Lite instance
  })
  .catch(error => {
    console.error('Error initializing Aladin Lite:', error);
  });

Throws:

Throws an error if WebGL2 is not supported by the browser.
Type string

Returns:

A promise that resolves once the initialization is complete.

Type: Promise.<void>

(static) marker(ra, dec, optionsopt, dataopt) → {Source}

Description:

Creates a marker at the specified celestial coordinates.

Source:

A.js, line 208

Example

const markerObj = A.marker(180.0, 30.0, data, options);

Parameters:

Name	Type	Attributes	Description
`ra`	number		Right Ascension (RA) coordinate in degrees.
`dec`	number		Declination (Dec) coordinate in degrees.
`options`	MarkerOptions	<optional>	Options for configuring the marker.
`data`	Object	<optional>	Additional data associated with the marker.

Returns:

A marker source object.

Type: Source

(static) polygon(radecArray, options) → {Polyline}

Description:

Creates a polygon object using an array of celestial coordinates (RA, Dec).

Source:

A.js, line 228

Parameters:

Name	Type	Description
`radecArray`	Array.<Array.<number>>	right-ascension/declination 2-tuple array describing the polyline's vertices in degrees
`options`	ShapeOptions	Options for configuring the polygon

Throws:

Throws an error if the number of vertices is less than 3.
Type string

Returns:

Type: Polyline

(static) polyline(radecArray, options) → {Polyline}

Description:

Creates a polyline shape

Source:

A.js, line 256

Parameters:

Name	Type	Description
`radecArray`	Array.<Array.<number>>	right-ascension/declination 2-tuple array describing the polyline's vertices in degrees
`options`	ShapeOptions	Options for configuring the polyline.

Returns:

Type: Polyline

(static) source(ra, dec, dataopt, optionsopt) → {Source}

Description:

Creates a celestial source object with the given coordinates.

Source:

A.js, line 190

Example

const sourceObj = A.source(180.0, 30.0, data, options);

Parameters:

Name	Type	Attributes	Description
`ra`	number		Right Ascension (RA) coordinate in degrees.
`dec`	number		Declination (Dec) coordinate in degrees.
`data`	Object	<optional>	Additional data associated with the source.
`options`	SourceOptions	<optional>	Options for configuring the source object.

Returns:

A celestial source object.

Type: Source

(static) vector(ra1, dec1, ra2, dec2, options) → {Vector}

Description:

Creates a vector shape

Source:

A.js, line 311

Parameters:

Name	Type	Description
`ra1`	number	Right Ascension (RA) coordinate of the center in degrees.
`dec1`	number	Declination (Dec) coordinate of the center in degrees.
`ra2`	number	Right Ascension (RA) coordinate of the center in degrees.
`dec2`	number	Declination (Dec) coordinate of the center in degrees.
`options`	ShapeOptions	Options for configuring the vector.

Returns:

Type: Vector