Point

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});

• Points with constraints