Circles on circles rotating in opposite directions: Difference between revisions

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This is an example of a parametric curve plot. It shows the orbit of a point on a circle. The circle rotates on a circle which again rotates on the unit circle. The resulting curve is described by the function
This is an example of a parametric curve plot. It shows the orbit of a point on a circle. The circle rotates on a circle which again rotates on the unit circle. The resulting curve is described by the function
:<math> [0,2\pi]\to{\mathbf R}^2, \quad t\mapsto {\cos(t)\choose \sin(t)}+c_1{\cos(f_1t)\choose \sin(f_1t)}+c_2{\sin(f_2t)\choose \cos(f_2t)}</math>
:<math> [0,2\pi]\to{\mathbf R}^2, \quad t\mapsto {\cos(t)\choose \sin(t)}+c_1{\cos(f_1t)\choose \sin(f_1t)}+c_2{\sin(f_2t)\choose \cos(f_2t)}</math>
The sliders to adjust the parameters of this curve are from the jQuery UI package, see [http://jqueryui.com http://jqueryui.com]. This example shows the seamless integration of JSXGraph into the web page.
 
This example shows the seamless integration of JSXGraph into the web page.


<html>
<html>
<div class="sliders" style="margin:5px">
  <p>
<div style="margin:5px">
<div style="margin:5px">
   <p>
   <p>
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         oninput="f2 = this.value; board.update();"  
         oninput="f2 = this.value; board.update();"  
     />
     />
  </p>
</div>
   </p>
   </p>
</div>
</div>
Line 62: Line 59:
This is the first experiment with the jQuery UI package. So, the code may not be optimized, yet. The main difficulty is to read the values of the sliders. This is done via four JavaScript variables <math>c1, c2, f1, f2</math>.
This is the first experiment with the jQuery UI package. So, the code may not be optimized, yet. The main difficulty is to read the values of the sliders. This is done via four JavaScript variables <math>c1, c2, f1, f2</math>.
<source lang="html4strict">
<source lang="html4strict">
<html>
<div style="margin:5px">
<link rel="Stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/css/ui-lightness/jquery-ui-1.7.2.custom.css"/>
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jquery.min.js"></script>
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jquery-ui.min.js"></script>
 
<style type="text/css">
#slider-frame > div.sliders { padding: 10px !important; };
</style>
<script type="text/javascript">
$(function() {
$("#sliderc1").slider({
orientation: "horizontal",range: "min",min: 0,max: 100,value: 60,
slide: function(event, ui) {
$("#c1").val(ui.value*0.01);
                                c1 = ui.value*0.01;
                                board.update();
}
});
$("#sliderf1").slider({
orientation: "horizontal",range: "min",min: 1,max: 100,value: 7,
slide: function(event, ui) {
$("#f1").val(ui.value);
                                f1 = ui.value;
                                board.update();
}
});
$("#c1").val($("#sliderc1").slider("value")*0.01);
$("#f1").val($("#sliderf1").slider("value"));
 
$("#sliderc2").slider({
orientation: "horizontal",range: "min",min: 0,max: 100,value: 0,
slide: function(event, ui) {
$("#c2").val(ui.value*0.01);
                                c2 = ui.value*0.01;
                                board.update();
}
});
$("#sliderf2").slider({
orientation: "horizontal",range: "min",min: 1,max: 100,value: 17,
slide: function(event, ui) {
$("#f2").val(ui.value);
                                f2 = ui.value;
                                board.update();
}
});
$("#c2").val($("#sliderc2").slider("value")*0.01);
$("#f2").val($("#sliderf2").slider("value"));
});
</script>
 
<div class="sliders" style="margin:5px">
   <p>
   <p>
     <label for="c1">c1:</label>
     <label for="c1">c1:</label>
     <input type="text" id="c1" style="border:0; color:#f6931f; font-weight:bold;" />
     <input type="range" id="c1" style="border:0; color:#f6931f; font-weight:bold;"  
        min="0" max="100" value="60"
        oninput="c1 = this.value*0.01; board.update();"
    />
     <label for="f1">f1:</label>
     <label for="f1">f1:</label>
     <input type="text" id="f1" style="border:0; color:#f6931f; font-weight:bold;" />
     <input type="range" id="f1" style="border:0; color:#f6931f; font-weight:bold;"  
        min="1" max="100" value="7"
        oninput="f1 = this.value; board.update();"
    />
     <label for="c2">c2:</label>
     <label for="c2">c2:</label>
     <input type="text" id="c2" style="border:0; color:#f6931f; font-weight:bold;" />
     <input type="range" id="c2" style="border:0; color:#f6931f; font-weight:bold;"  
        min="0" max="100" value="0"
        oninput="c2 = this.value*0.01;
                  board.updateQuality = board.BOARD_QUALITY_HIGH;
                  board.update();"
    />
     <label for="f2">f2:</label>
     <label for="f2">f2:</label>
     <input type="text" id="f2" style="border:0; color:#f6931f; font-weight:bold;" />
     <input type="range" id="f2" style="border:0; color:#f6931f; font-weight:bold;"  
        min="1" max="100" value="17"
        oninput="f2 = this.value; board.update();"
    />
   </p>
   </p>
  <div id="sliderc1" style="width:300px;margin:10px;"></div>
  <div id="sliderf1" style="width:300px;margin:10px;"></div>
  <div id="sliderc2" style="width:300px;margin:10px;"></div>
  <div id="sliderf2" style="width:300px;margin:10px;"></div>
</div>
</div>
</html>
 
<jsxgraph width="500" height="500" box="jxgbox">
<jsxgraph width="500" height="500" box="jxgbox">
board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2.5,2.5,2.5,-2.5], keepaspectratio:true});
board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2.5,2.5,2.5,-2.5], keepaspectratio:true});
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               function(t) { return Math.cos(t)+ c1*Math.cos(f1*t)+ c2*Math.sin(f2*t);},
               function(t) { return Math.cos(t)+ c1*Math.cos(f1*t)+ c2*Math.sin(f2*t);},
               function(t) { return Math.sin(t)+ c1*Math.sin(f1*t)+ c2*Math.cos(f2*t);},
               function(t) { return Math.sin(t)+ c1*Math.sin(f1*t)+ c2*Math.cos(f2*t);},
               0,2.02*Math.PI],{strokeWidth:2});
               0,2.02*Math.PI], {strokeWidth:2});
</script>
</script>
</source>
</source>
[[Category:Examples]]
[[Category:Examples]]
[[Category:Curves]]
[[Category:Curves]]

Revision as of 12:16, 23 June 2020

This is an example of a parametric curve plot. It shows the orbit of a point on a circle. The circle rotates on a circle which again rotates on the unit circle. The resulting curve is described by the function

[math]\displaystyle{ [0,2\pi]\to{\mathbf R}^2, \quad t\mapsto {\cos(t)\choose \sin(t)}+c_1{\cos(f_1t)\choose \sin(f_1t)}+c_2{\sin(f_2t)\choose \cos(f_2t)} }[/math]

This example shows the seamless integration of JSXGraph into the web page.

Variation:

External references

Epicycloidal curves have been used by the ancient greeks to describe the orbits of the planets, see

The source code of this construction

This is the first experiment with the jQuery UI package. So, the code may not be optimized, yet. The main difficulty is to read the values of the sliders. This is done via four JavaScript variables [math]\displaystyle{ c1, c2, f1, f2 }[/math].

<div style="margin:5px">
  <p>
    <label for="c1">c1:</label>
    <input type="range" id="c1" style="border:0; color:#f6931f; font-weight:bold;" 
        min="0" max="100" value="60" 
        oninput="c1 = this.value*0.01; board.update();" 
    />
    <label for="f1">f1:</label>
    <input type="range" id="f1" style="border:0; color:#f6931f; font-weight:bold;" 
        min="1" max="100" value="7"
        oninput="f1 = this.value; board.update();" 
    />
    <label for="c2">c2:</label>
    <input type="range" id="c2" style="border:0; color:#f6931f; font-weight:bold;" 
        min="0" max="100" value="0"
        oninput="c2 = this.value*0.01; 
                  board.updateQuality = board.BOARD_QUALITY_HIGH;
                  board.update();" 
    />
    <label for="f2">f2:</label>
    <input type="range" id="f2" style="border:0; color:#f6931f; font-weight:bold;" 
        min="1" max="100" value="17"
        oninput="f2 = this.value; board.update();" 
    />
  </p>
</div>

<jsxgraph width="500" height="500" box="jxgbox">
board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-2.5,2.5,2.5,-2.5], keepaspectratio:true});
var c1 = 0.6;
var c2 = 0.0; 
var f1 = 7; 
var f2 = 17;
var c = board.create('curve', [
              function(t) { return Math.cos(t)+ c1*Math.cos(f1*t)+ c2*Math.sin(f2*t);},
              function(t) { return Math.sin(t)+ c1*Math.sin(f1*t)+ c2*Math.cos(f2*t);},
              0,2.02*Math.PI], {strokeWidth:2});
</script>