Lituus: Difference between revisions

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<jsxgraph width="500" height="500" box="box1">
<jsxgraph width="500" height="500" box="box1">
  var b1 = JXG.JSXGraph.initBoard('box1', {axis:true,originX: 250, originY: 250, unitX: 25, unitY: 25});
  var b1 = JXG.JSXGraph.initBoard('box1', {axis:true,boundingbox: [-10, 10, 10, -10]});
  var k = b1.createElement('slider', [[1,8],[5,8],[0,1,4]]);
  var k = b1.create('slider', [[1,8],[5,8],[0,1,4]]);
  var c = b1.createElement('curve', [function(phi){return Math.sqrt(k.Value()/phi); }, [0, 0],0, 8*Math.PI],
  var c = b1.create('curve', [function(phi){return Math.sqrt(k.Value()/phi); }, [0, 0],0, 8*Math.PI],
             {curveType:'polar', strokewidth:4});       
             {curveType:'polar', strokewidth:1});       
</jsxgraph>
</jsxgraph>


===The JavaScript code to produce this picture===
===The JavaScript code to produce this picture===


<source lang="xml">
<source lang="javascript">
<jsxgraph width="500" height="500" box="box1">
var b1 = JXG.JSXGraph.initBoard('box1', {axis:true,boundingbox: [-10, 10, 10, -10]});
var b1 = JXG.JSXGraph.initBoard('box1', {axis:true,originX: 250, originY: 250, unitX: 25, unitY: 25});
var k = b1.create('slider', [[1,8],[5,8],[0,1,4]]);
var k = b1.createElement('slider', [[1,8],[5,8],[0,1,4]]);
var c = b1.create('curve', [function(phi){return Math.sqrt(k.Value()/phi); }, [0, 0],0, 8*Math.PI],
var c = b1.createElement('curve', [function(phi){return Math.sqrt(k.Value()/phi); }, [0, 0],0, 8*Math.PI],
             {curveType:'polar', strokewidth:1});       
             {curveType:'polar', strokewidth:4});       
</jsxgraph>
</source>
</source>
<jsxgraph width="500" height="500" box="box2">
var b2 = JXG.JSXGraph.initBoard('box2', {axis:true,originX: 250, originY: 250, unitX: 25, unitY: 25});
var k = b2.createElement('slider', [[1,8],[5,8],[0,1,4]]);
var c = b2.createElement('curve', [function(phi){return Math.cos(2.0*phi); }, [0, 0],0, 4*Math.PI],
            {curveType:'polar', strokewidth:4});     
</jsxgraph>


===External links===
===External links===

Latest revision as of 08:35, 8 June 2011

A lituus is a spiral in which the angle is inversely proportional to the square of the radius (as expressed in polar coordinates).

[math]\displaystyle{ r^2\theta = k \, }[/math]

The JavaScript code to produce this picture

var b1 = JXG.JSXGraph.initBoard('box1', {axis:true,boundingbox: [-10, 10, 10, -10]});
var k = b1.create('slider', [[1,8],[5,8],[0,1,4]]);
var c = b1.create('curve', [function(phi){return Math.sqrt(k.Value()/phi); }, [0, 0],0, 8*Math.PI],
             {curveType:'polar', strokewidth:1});

External links