Rolling circle on line: Difference between revisions

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Line 1: Line 1:
<jsxgraph width="0" height="0" box="nix"></jsxgraph>
<html>
<html>
<script type="text/javascript" src="/~alfred/jsxgraph/trunk/src/Roulette.js"></script>
<form>
<form>
<input type="button" value="start" onclick="rol.start()">
<input type="button" value="start" onclick="rol.start()">
Line 19: Line 17:
var C = brd.create('point',[0,2],{name:'C'});
var C = brd.create('point',[0,2],{name:'C'});
var circle = brd.create('curve',[
var circle = brd.create('curve',[
                     function(t){var d = P.Dist(C);
                     function(t){var d = P.Dist(C),
                                    beta = JXG.Math.Geometry.rad([C.X()+1,C.Y()],C,P);
                                t += beta;
                                 return C.X()+d*Math.cos(t);
                                 return C.X()+d*Math.cos(t);
                     },
                     },
                     function(t){var d = P.Dist(C);
                     function(t){var d = P.Dist(C),
                                    beta = JXG.Math.Geometry.rad([C.X()+1,C.Y()],C,P);
                                t += beta;
                                 return C.Y()+d*Math.sin(t);
                                 return C.Y()+d*Math.sin(t);
                     },
                     },
Line 32: Line 34:
brd.create('segment',[C,B],{color:'black'});  
brd.create('segment',[C,B],{color:'black'});  
brd.unsuspendUpdate();
brd.unsuspendUpdate();
var rol = JXG.Math.Numerics.createRoulette(line, circle, 0, Math.PI/20, 1, 100, [C,P,B]);  
var rol = brd.createRoulette(line, circle, 0, Math.PI/20, 1, 100, [C,P,B]);  


</jsxgraph>
</jsxgraph>
Line 38: Line 40:
===The underlying JavaScript code===
===The underlying JavaScript code===
<source lang="javascript">
<source lang="javascript">
var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-1,5,20,-1], keepaspectratio:true});
brd.suspendUpdate();
// Line
var line = brd.create('curve', [function(t) { return t;}, function(t){ return 1;}], {strokeWidth:6});
// Circle
var P = brd.create('point',[0,1],{name:'P', trace:true});
var C = brd.create('point',[0,2],{name:'C'});
var circle = brd.create('curve',[
                    function(t){var d = P.Dist(C),
                                    beta = JXG.Math.Geometry.rad([C.X()+1,C.Y()],C,P);
                                t += beta;
                                return C.X()+d*Math.cos(t);
                    },
                    function(t){var d = P.Dist(C),
                                    beta = JXG.Math.Geometry.rad([C.X()+1,C.Y()],C,P);
                                t += beta;
                                return C.Y()+d*Math.sin(t);
                    },
                    0,2*Math.PI],
                    {strokeWidth:6, strokeColor:'green'});
// Point on circle
var B = brd.create('glider',[0,2,circle],{name:'B', color:'blue',trace:false});
brd.create('segment',[C,B],{color:'black'});
brd.unsuspendUpdate();
var rol = brd.createRoulette(line, circle, 0, Math.PI/20, 1, 100, [C,P,B]);
</source>
</source>



Latest revision as of 17:20, 23 November 2010

The underlying JavaScript code

var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-1,5,20,-1], keepaspectratio:true});
brd.suspendUpdate();

// Line
var line = brd.create('curve', [function(t) { return t;}, function(t){ return 1;}], {strokeWidth:6});

// Circle
var P = brd.create('point',[0,1],{name:'P', trace:true});
var C = brd.create('point',[0,2],{name:'C'});
var circle = brd.create('curve',[
                    function(t){var d = P.Dist(C),
                                    beta = JXG.Math.Geometry.rad([C.X()+1,C.Y()],C,P);
                                t += beta;
                                return C.X()+d*Math.cos(t);
                    },
                    function(t){var d = P.Dist(C),
                                    beta = JXG.Math.Geometry.rad([C.X()+1,C.Y()],C,P);
                                t += beta;
                                return C.Y()+d*Math.sin(t);
                    },
                    0,2*Math.PI],
                    {strokeWidth:6, strokeColor:'green'});

// Point on circle
var B = brd.create('glider',[0,2,circle],{name:'B', color:'blue',trace:false});
brd.create('segment',[C,B],{color:'black'}); 
brd.unsuspendUpdate();
var rol = brd.createRoulette(line, circle, 0, Math.PI/20, 1, 100, [C,P,B]);