Difference between revisions of "Even simpler function plotter"
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Jump to navigationJump to searchA WASSERMANN (talk | contribs) |
A WASSERMANN (talk | contribs) |
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Line 64: | Line 64: | ||
<input type="button" value="plot" onClick="plotter()"> | <input type="button" value="plot" onClick="plotter()"> | ||
<input type="button" value="clear all" onClick="clearAll()"> | <input type="button" value="clear all" onClick="clearAll()"> | ||
+ | <input type="button" value="add tangent" onClick="addTangent()"> | ||
+ | <input type="button" value="add Derivative" onClick="addDerivative()"> | ||
</source> | </source> | ||
<source lang="javascript"> | <source lang="javascript"> | ||
var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true}); | var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true}); | ||
+ | var f, curve; // global objects | ||
function plotter() { | function plotter() { | ||
− | var | + | var txt = JXG.GeonextParser.geonext2JS(document.getElementById('input').value); |
− | + | f = new Function('x','var y = '+txt+'; return y;'); | |
− | board.create('functiongraph',[f, | + | curve = board.create('functiongraph',[f, |
function(){ | function(){ | ||
var c = new JXG.Coords(JXG.COORDS_BY_SCREEN,[0,0],board); | var c = new JXG.Coords(JXG.COORDS_BY_SCREEN,[0,0],board); | ||
Line 82: | Line 85: | ||
]); | ]); | ||
} | } | ||
+ | |||
function clearAll() { | function clearAll() { | ||
JXG.JSXGraph.freeBoard(board); | JXG.JSXGraph.freeBoard(board); | ||
board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true}); | board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true}); | ||
+ | f = null; | ||
+ | curve = null; | ||
+ | } | ||
+ | |||
+ | function addTangent() { | ||
+ | if (JXG.isFunction(f)) { | ||
+ | board.suspendUpdate(); | ||
+ | var p = board.create('glider',[1,0,curve], {name:'drag me'}); | ||
+ | board.create('tangent',[p], {name:'drag me'}); | ||
+ | board.unsuspendUpdate(); | ||
+ | } | ||
+ | } | ||
+ | |||
+ | function addDerivative() { | ||
+ | if (JXG.isFunction(f)) { | ||
+ | board.create('functiongraph',[JXG.Math.Numerics.D(f), | ||
+ | function(){ | ||
+ | var c = new JXG.Coords(JXG.COORDS_BY_SCREEN,[0,0],board); | ||
+ | return c.usrCoords[1]; | ||
+ | }, | ||
+ | function(){ | ||
+ | var c = new JXG.Coords(JXG.COORDS_BY_SCREEN,[board.canvasWidth,0],board); | ||
+ | return c.usrCoords[1]; | ||
+ | } | ||
+ | ], {dash:2}); | ||
+ | } | ||
} | } | ||
</source> | </source> |
Revision as of 15:15, 15 July 2010
The underlying JavaScript code
<input type="text" id="input" value="sin(x)*x">
<input type="button" value="plot" onClick="plotter()">
<input type="button" value="clear all" onClick="clearAll()">
<input type="button" value="add tangent" onClick="addTangent()">
<input type="button" value="add Derivative" onClick="addDerivative()">
var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true});
var f, curve; // global objects
function plotter() {
var txt = JXG.GeonextParser.geonext2JS(document.getElementById('input').value);
f = new Function('x','var y = '+txt+'; return y;');
curve = board.create('functiongraph',[f,
function(){
var c = new JXG.Coords(JXG.COORDS_BY_SCREEN,[0,0],board);
return c.usrCoords[1];
},
function(){
var c = new JXG.Coords(JXG.COORDS_BY_SCREEN,[board.canvasWidth,0],board);
return c.usrCoords[1];
}
]);
}
function clearAll() {
JXG.JSXGraph.freeBoard(board);
board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true});
f = null;
curve = null;
}
function addTangent() {
if (JXG.isFunction(f)) {
board.suspendUpdate();
var p = board.create('glider',[1,0,curve], {name:'drag me'});
board.create('tangent',[p], {name:'drag me'});
board.unsuspendUpdate();
}
}
function addDerivative() {
if (JXG.isFunction(f)) {
board.create('functiongraph',[JXG.Math.Numerics.D(f),
function(){
var c = new JXG.Coords(JXG.COORDS_BY_SCREEN,[0,0],board);
return c.usrCoords[1];
},
function(){
var c = new JXG.Coords(JXG.COORDS_BY_SCREEN,[board.canvasWidth,0],board);
return c.usrCoords[1];
}
], {dash:2});
}
}