Point

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Construction of a free point

This example shows how to construct a simple, draggable point. It is produced by the following commands:

<div id="jxgbox" class="jxgbox" style="width:500px; height:200px;"></div>
<script type="text/javascript">
 var board = JXG.JSXGraph.initBoard('jxgbox', {originX: 200, originY: 100, unitX: 50, unitY: 50});
 var p = board.createElement('point',[1,1]);
</script>

The JavaScript code has to be placed AFTER the div element which will contain the construction. From now on, we will only show the JavaScript code.

Attributes of a point

User defined name

Several attributes can be given to change the properties of a point, for example a name.

var b2 = JXG.JSXGraph.initBoard('jxgbox2', {originX: 200, originY: 100, unitX: 50, unitY: 50});
var p = b2.createElement('point',[1,1], {name:'X',style:5});

This point will be labeled with "X":

Point styles

The property type of a point can attain the values 0..12. Alternatively you can use these equivalent constants for that:

Constant Value Short description
JXG.POINT_STYLE_X_SMALL 0 Small x
JXG.POINT_STYLE_X 1 Medium x
JXG.POINT_STYLE_X_BIG 2 Big x
JXG.POINT_STYLE_CIRCLE_TINY 3 Tiny circle
JXG.POINT_STYLE_CIRCLE_SMALL 4 Small circle
JXG.POINT_STYLE_CIRCLE 5 Medium circle
JXG.POINT_STYLE_CIRCLE_BIG 6 Big circle
JXG.POINT_STYLE_SQUARE_SMALL 7 Small square
JXG.POINT_STYLE_SQUARE 8 Medium square
JXG.POINT_STYLE_SQUARE_BIG 9 Big square
JXG.POINT_STYLE_PLUS_SMALL 10 Small +
JXG.POINT_STYLE_PLUS 11 Medium +
JXG.POINT_STYLE_PLUS_BIG 12 Big +

In this examples we use a for loop to create 13 points.

var b3 = JXG.JSXGraph.initBoard('jxgbox3', {originX: 40, originY: 100, unitX: 40, unitY: 40});
for (var i=0;i<13;i++) {
  var p = b3.createElement('point',[i,0], {name:'P_{'+i+'}', style:i});
}

Fixed points

A property of an element may also be set after creating it. In the above example we set the property fixed of the last point, P_12, to true. I.e. the point is no longer draggable.

p.setProperty({fixed:true});