Packageflare.vis.operator.filter
Classpublic class FisheyeTreeFilter
InheritanceFisheyeTreeFilter Inheritance Operator

Filter operator that computes a fisheye degree-of-interest function over a tree structure. Visibility and DOI (degree-of-interest) values are set for the nodes and edges in the structure. This function includes a set of focus nodes, and includes neighbors only in a limited window around these foci. The size of this window is determined by this operator's distance property. All ancestors of a focus up to the root of the tree are considered foci as well. By convention, DOI values start at zero for focus nodes, with decreasing negative numbers for each hop away from a focus. The DOI values computed by this filter are stored in the DataSprite.props.doi property.

This form of filtering was described by George Furnas as early as 1981. For more information about Furnas' fisheye view calculation and DOI values, take a look at G.W. Furnas, "The FISHEYE View: A New Look at Structured Files," Bell Laboratories Tech. Report, Murray Hill, New Jersey, 1981. Available online at http://citeseer.nj.nec.com/furnas81fisheye.html.


Public Properties
 PropertyDefined by
  distance : int
Graph distance within within which items wll be visible.
FisheyeTreeFilter
 Inheritedenabled : Boolean
Indicates if the operator is enabled or disabled.
Operator
  focusNodes : Array
An array of focal NodeSprites.
FisheyeTreeFilter
 Inheritedparameters : Object
Sets parameter values for this operator.
Operator
 Inheritedvisualization : Visualization
The visualization processed by this operator.
Operator
Public Methods
 MethodDefined by
  
FisheyeTreeFilter(focusNodes:Array = null, distance:int = 1)
Creates a new FisheyeTreeFilter
FisheyeTreeFilter
 Inherited
applyParameters(op:IOperator, params:Object):void
[static] Static method that applies parameter settings to an operator.
Operator
  
operate(t:Transitioner = null):void
Performs an operation over the contents of a visualization.
FisheyeTreeFilter
 Inherited
setup():void
Setup method invoked whenever this operator's visualization property is set.
Operator
Property detail
distanceproperty
public var distance:int

Graph distance within within which items wll be visible.

focusNodesproperty 
public var focusNodes:Array

An array of focal NodeSprites.

Constructor detail
FisheyeTreeFilter()constructor
public function FisheyeTreeFilter(focusNodes:Array = null, distance:int = 1)

Creates a new FisheyeTreeFilter

Parameters
focusNodes:Array (default = null) — focusNodes an array of focal NodeSprites. Graph distance is measured as the minimum number of edge-hops to one of these nodes or their ancestors up to the root.
 
distance:int (default = 1) — graph distance within which items will be visible
Method detail
operate()method
public override function operate(t:Transitioner = null):void

Performs an operation over the contents of a visualization.

Parameters
t:Transitioner (default = null) — a Transitioner instance for collecting value updates.



© 2007-2008 Regents of the University of California. Created Sat Jan 24 2009 11:25 AM.