Bearing: Difference between revisions
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<jsxgraph box="box2" width="600" height="500"> | <jsxgraph box="box2" width="600" height="500"> | ||
var brd2 = JXG.JSXGraph.initBoard('box2',{axis:true,boundingbox:[-2,1.5,2,-1.5],keepaspectratio:true}); | var brd2 = JXG.JSXGraph.initBoard('box2',{axis:true,boundingbox:[-2,1.5,2,-1.5],keepaspectratio:true}); | ||
var | var p1 = brd2.create('point',[0,0]); | ||
var p2 = brd2.create('point',[1,0]); | |||
var p3 = brd2.create('point',[0,1]); | |||
var a = brd2.create('arc',[p1,p2,p3]); | |||
var q = brd2.create('glider',[-1,0.5,a],{name:'drag me'}); // global variable | var q = brd2.create('glider',[-1,0.5,a],{name:'drag me'}); // global variable | ||
brd2.addHook(function(){ | brd2.addHook(function(){ | ||
Revision as of 16:30, 16 June 2010
The underlying JavaScript code
<form>
<input type="text" id="degrees">
<input type="button" value="set direction" onclick="setDirection()">
</form>
var brd = JXG.JSXGraph.initBoard('jxgbox',{axis:true,boundingbox:[-2,1.5,2,-1.5],keepaspectratio:true});
var c = brd.create('circle',[[0,0],1]);
var p = brd.create('glider',[-1,0.5,c],{name:'drag me'}); // global variable
brd.addHook(function(){
document.getElementById('degrees').value = (Math.atan2(p.Y(),p.X())*180/Math.PI).toFixed(0);
});
var setDirection = function() {
var phi = 1*document.getElementById('degrees').value*Math.PI/180.0;
var r = c.Radius();
p.moveTo([r*Math.cos(phi),r*Math.sin(phi)]);
}
Version 2
