Archimedean spiral: Difference between revisions
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| A WASSERMANN (talk | contribs) No edit summary | No edit summary | ||
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| It can be described in polar coordinates <math>(r, \theta)</math> by the equation | It can be described in polar coordinates <math>(r, \theta)</math> by the equation | ||
| Line 9: | Line 4: | ||
| with real numbers <math>a</math> and <math>b</math>. | with real numbers <math>a</math> and <math>b</math>. | ||
| < | <jsxgraph height="500" width="500" box="jxgbox"> | ||
| var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-10, 10, 10, -10]}); | |||
| var a = board.create('slider', [[1,8],[5,8],[0,1,4]],{name:'a'}); | |||
| var b = board.create('slider', [[1,9],[5,9],[0,0.25,4]],{name:'b'}); | |||
| var c = board.create('curve', [function(phi){return a.Value()+b.Value()*phi; }, [0, 0],0, 8*Math.PI], | |||
|               {curveType:'polar', strokewidth:4});        |               {curveType:'polar', strokewidth:4});        | ||
| var g = board.create('glider', [c]); | |||
| var t = board.create('tangent', [g], {dash:2,strokeColor:'#a612a9'}); | |||
| </ | var n = board.create('normal', [g], {dash:2,strokeColor:'#a612a9'}); | ||
| </jsxgraph> | |||
| ===The JavaScript code to produce this picture=== | ===The JavaScript code to produce this picture=== | ||
| <source lang="javascript"> | <source lang="javascript"> | ||
| var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-10, 10, 10, -10]}); | |||
| var a = board.create('slider', [[1,8],[5,8],[0,1,4]],{name:'a'}); | |||
| var b = board.create('slider', [[1,9],[5,9],[0,0.25,4]],{name:'b'}); | |||
|               {curveType:'polar', strokewidth:4});  | var c = board.create('curve', [function(phi){return a.Value()+b.Value()*phi; }, [0, 0],0, 8*Math.PI], | ||
|               {curveType:'polar', strokewidth:4});       | |||
| var g = board.create('glider', [c]); | |||
| var t = board.create('tangent', [g], {dash:2,strokeColor:'#a612a9'}); | |||
| var n = board.create('normal', [g], {dash:2,strokeColor:'#a612a9'}); | |||
| </source> | </source> | ||
| [[Category:Examples]] | [[Category:Examples]] | ||
| [[Category:Curves]] | [[Category:Curves]] | ||
Latest revision as of 11:35, 7 June 2011
It can be described in polar coordinates [math]\displaystyle{ (r, \theta) }[/math] by the equation
- [math]\displaystyle{ \, r=a+b\theta }[/math]
with real numbers [math]\displaystyle{ a }[/math] and [math]\displaystyle{ b }[/math].
The JavaScript code to produce this picture
var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox: [-10, 10, 10, -10]});
var a = board.create('slider', [[1,8],[5,8],[0,1,4]],{name:'a'});
var b = board.create('slider', [[1,9],[5,9],[0,0.25,4]],{name:'b'});
var c = board.create('curve', [function(phi){return a.Value()+b.Value()*phi; }, [0, 0],0, 8*Math.PI],
             {curveType:'polar', strokewidth:4});      
var g = board.create('glider', [c]);
var t = board.create('tangent', [g], {dash:2,strokeColor:'#a612a9'});
var n = board.create('normal', [g], {dash:2,strokeColor:'#a612a9'});