JSXGraph Reference
ElementsElement PolePoint
JXG.GeometryElement
↳ JXG.Point
↳ PolePoint
This element is used to provide a constructor for the pole point of a line with respect to a conic or a circle.
Defined in: point.js.
Extends
JXG.Point.
| Constructor Attributes | Constructor Name and Description |
|---|---|
|
The pole point is the unique reciprocal relationship of a line with respect to a conic.
|
- Methods borrowed from class JXG.Point:
- _anim, addConstraint, addTransform, Dist, free, handleAttractors, handleSnapToPoints, hasPoint, makeGlider, moveAlong, moveTo, normalizeFace, popSlideObject, remove, setGliderPosition, setPosition, setPositionByTransform, setPositionDirectly, setStyle, update, updateConstraint, updateGlider, updateGliderFromParent, updateRenderer, updateTransform, visit, X, XEval, Y, YEval, Z, ZEval
- Methods borrowed from class JXG.GeometryElement:
- _set, addChild, addDescendants, addRotation, animate, bounds, clearTrace, cloneToBackground, countChildren, createGradient, createLabel, draggable, generatePolynomial, getAttribute, getAttributes, getLabelAnchor, getName, getParents, getTextAnchor, getType, handleSnapToGrid, hideElement, labelColor, noHighlight, normalize, off, on, prepareUpdate, removeChild, removeDescendants, resolveShortcuts, setArrow, setAttribute, setDash, setLabelText, setName, showElement, triggerEventHandlers
- Events borrowed from class JXG.GeometryElement:
- attribute, attribute:<attribute><attribute>, down, drag, mousedown, mousedrag, mousemove, mouseout, mouseover, mouseup, move, out, over, touchdown, touchdrag, touchup, up
Element Detail
PolePoint
The pole point is the unique reciprocal relationship of a line with respect to a conic.
The lines tangent to the intersections of a conic and a line intersect at the pole point of that line with respect to that conic.
A line tangent to a conic has the pole point of that line with respect to that conic as the tangent point.
See http://en.wikipedia.org/wiki/Pole_and_polar for more information on pole and polar.
-
This element has no direct constructor. To create an instance of this element you have to call JXG.Board#create
with type "polepoint".
- Possible parent array combinations are:
-
{JXG.Conic|JXG.Circle} el1
{JXG.Point} el2
- or
-
{JXG.Point} el1
{JXG.Conic|JXG.Circle} el2
- The result will be the pole point of the line with respect to the conic or the circle.
- Throws:
- {Exception}
- If the element cannot be constructed with the given parent objects an exception is thrown.
- Examples:
// Create the pole point of a line with respect to a conic
var p1 = board.create('point', [-1, 2]);
var p2 = board.create('point', [ 1, 4]);
var p3 = board.create('point', [-1,-2]);
var p4 = board.create('point', [ 0, 0]);
var p5 = board.create('point', [ 4,-2]);
var c1 = board.create('conic',[p1,p2,p3,p4,p5]);
var p6 = board.create('point', [-1, 4]);
var p7 = board.create('point', [2, -2]);
var l1 = board.create('line', [p6, p7]);
var p8 = board.create('polepoint', [c1, l1]);
// Create the pole point of a line with respect to a circle
var p1 = board.create('point', [1, 1]);
var p2 = board.create('point', [2, 3]);
var c1 = board.create('circle',[p1,p2]);
var p3 = board.create('point', [-1, 4]);
var p4 = board.create('point', [4, -1]);
var l1 = board.create('line', [p3, p4]);
var p5 = board.create('polepoint', [c1, l1]);
Attributes borrowed from other Elements
- Attributes borrowed from class JXG.Point:
- attractorDistance, attractors, face, showInfobox, size, snapSizeX, snapSizeY, snapToGrid, snapToPoints, snatchDistance, style
- Attributes borrowed from class JXG.GeometryElement:
- dash, draft, fillColor, fillOpacity, fixed, frozen, highlight, highlightFillColor, highlightFillOpacity, highlightStrokeColor, highlightStrokeOpacity, highlightStrokeWidth, needsRegularUpdate, scalable, shadow, strokeColor, strokeOpacity, strokeWidth, trace, traceAttributes, visible, withLabel
Fields borrowed from other Elements
- Fields borrowed from class JXG.Point:
- coords, group, needsUpdateFromParent, onPolygon, position, slideObjects
- Fields borrowed from class JXG.GeometryElement:
- _pos, addEvent, ancestors, baseElement, board, childElements, descendants, dump, elementClass, elType, eventHandlers, getProperty, hasLabel, highlighted, id, isDraggable, isReal, lastDragTime, methodMap, mouseover, name, needsUpdate, notExistingParents, numTraces, quadraticform, removeEvent, rendNode, setProperty, stdform, subs, symbolic, traces, transformations, type, visProp
Methods borrowed from other Elements
- Methods borrowed from class JXG.Point:
- _anim, addConstraint, addTransform, Dist, free, handleAttractors, handleSnapToPoints, hasPoint, makeGlider, moveAlong, moveTo, normalizeFace, popSlideObject, remove, setGliderPosition, setPosition, setPositionByTransform, setPositionDirectly, setStyle, update, updateConstraint, updateGlider, updateGliderFromParent, updateRenderer, updateTransform, visit, X, XEval, Y, YEval, Z, ZEval
- Methods borrowed from class JXG.GeometryElement:
- _set, addChild, addDescendants, addRotation, animate, bounds, clearTrace, cloneToBackground, countChildren, createGradient, createLabel, draggable, generatePolynomial, getAttribute, getAttributes, getLabelAnchor, getName, getParents, getTextAnchor, getType, handleSnapToGrid, hideElement, labelColor, noHighlight, normalize, off, on, prepareUpdate, removeChild, removeDescendants, resolveShortcuts, setArrow, setAttribute, setDash, setLabelText, setName, showElement, triggerEventHandlers
Events borrowed from other Elements