Parabola: Difference between revisions

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That means the numbers below ''a'', ''b'', and ''c'' are updated if the points ''A'', ''B'', and ''C'' are dragged. And other way round,
That means the numbers below ''a'', ''b'', and ''c'' are updated if the points ''A'', ''B'', and ''C'' are dragged. And other way round,
these numbers are editable.
these numbers are editable.
<jsxgraph box="box2" width="600" height="400">
hook = true;
board2 = JXG.JSXGraph.loadBoardFromString('box2', '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', 'Geonext');
</jsxgraph>
<html>
<html>
<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/prototype.js"></script>
<script type="text/javascript" src="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraphcore.js"></script>
<div id="box" class="jxgbox" style="width:600px; height:400px;"></div>
<table style="border: 0px solid black; text-align: center" width="500px">
<table style="border: 0px solid black; text-align: center" width="500px">
<tr><td rowspan="2"><div id="box2" class='jxgbox' style="width:375.0px; height:150.0px; border:0px dashed black; "></div></td><th style="border: 1px solid black" width="100px">a</th><th style="border: 1px solid black" width="100px">b</th><th style="border: 1px solid black" width="100px">c</th></tr>
<tr><th style="border: 1px solid black" width="100px">a</th><th style="border: 1px solid black" width="100px">b</th><th style="border: 1px solid black" width="100px">c</th></tr>
<tr><td><input type="text" id="print_a" size="2" maxlength="7"  
<tr><td><input type="text" id="print_a" size="2" maxlength="7"  
     style="border:none; text-align:right; font-size:1.2em; "
     style="border:none; text-align:right; font-size:1.2em; "
Line 14: Line 14:
></td><td><input type="text" id="print_b" size="2" maxlength="7"  
></td><td><input type="text" id="print_b" size="2" maxlength="7"  
     style="border:none; text-align:right; font-size:1.2em; "
     style="border:none; text-align:right; font-size:1.2em; "
     onKeyUp="board2.getElement('B').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update(); board2.update(); board.update();" onfocus="hook=false;" onblur="hook=true"
     onKeyUp="board2.getElement('B').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update();" onfocus="hook=false;" onblur="hook=true"
></td><td><input type="text" id="print_c" size="2" maxlength="7"  
></td><td><input type="text" id="print_c" size="2" maxlength="7"  
     style="border:none; text-align:right; font-size:1.2em; "
     style="border:none; text-align:right; font-size:1.2em; "
     onKeyUp="board2.getElement('C').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update(); board2.update(); board.update();" onfocus="hook=false;" onblur="hook=true"
     onKeyUp="board2.getElement('C').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update();" onfocus="hook=false;" onblur="hook=true"
></td></tr>
></td></tr>
</table>
</table>
<script language="JavaScript">
</html>
hook = true;
board2 = JXG.JSXGraph.loadBoardFromString('box2', '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', 'Geonext');


board = JXG.JSXGraph.initBoard('box', {originX: 250, originY: 250, unitX: 50, unitY: 50});
<jsxgraph box="box" width="600" height="400">
// Axes
board = JXG.JSXGraph.initBoard('box', {boundingbox: [-5, 5, 7, -3], axis: true});
b1axisx = board.createElement('axis', [[0,0], [1,0]], {});
b1axisy = board.createElement('axis', [[0,0], [0,1]], {});


curve = board.createElement('curve', [function(t){ return t; }, function(t){ return JXG.GetReferenceFromParameter(board2, 'A').X()*t*t+JXG.GetReferenceFromParameter(board2, 'B').X()*t+JXG.GetReferenceFromParameter(board2, 'C').X(); }, "t", -10, 10]);
curve = board.createElement('functiongraph', [function(t){ return JXG.getReference(board2, 'A').X()*t*t+JXG.getReference(board2, 'B').X()*t+JXG.getReference(board2, 'C').X(); },-10, 10]);
function print_table(board) {
function print_table() {
   if (hook){
   if (hook){
     $('print_a').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'A').X(),2);
     document.getElementById('print_a').value = JXG.getReference(board2, 'A').X().toFixed(2);
     $('print_b').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'B').X(),2);
     document.getElementById('print_b').value = JXG.getReference(board2, 'B').X().toFixed(2);
     $('print_c').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'C').X(),2);
     document.getElementById('print_c').value = JXG.getReference(board2, 'C').X().toFixed(2);
   }
   }
};
};
 
board2.addChild(board);
print_table_id = board2.addHook(print_table);
print_table_id = board2.addHook(print_table);
</script>
</jsxgraph>


===The underlying JavaScript code===
===The underlying JavaScript code===
<source lang="html4strict">
<div id="box2" class='jxgbox' style="width:375px; height:150px;"></div>
<table style="border: 0px solid black; text-align: center" width="500px">
<tr>
  <th style="border: 1px solid black" width="100px">a</th>
  <th style="border: 1px solid black" width="100px">b</th>
  <th style="border: 1px solid black" width="100px">c</th>
</tr>
<tr>
  <td><input type="text" id="print_a" size="2" maxlength="7" style="border:none; text-align:right; font-size:1.2em; "
    onKeyUp="board2.getElement('A').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update();"
    onfocus="hook=false;" onblur="hook=true"
    ></td>
  <td><input type="text" id="print_b" size="2" maxlength="7"style="border:none; text-align:right; font-size:1.2em; "
    onKeyUp="board2.getElement('B').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update();"
    onfocus="hook=false;" onblur="hook=true
    ></td>
  <td><input type="text" id="print_c" size="2" maxlength="7" style="border:none; text-align:right; font-size:1.2em; "
    onKeyUp="board2.getElement('C').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update();"
    onfocus="hook=false;" onblur="hook=true"
  ></td>
</tr>
</table> 
<div id="box" class="jxgbox" style="width:600px; height:400px;"></div>
</source>
<source lang="javascript">
<source lang="javascript">
hook = true;
hook = true;
board2 = JXG.JSXGraph.loadBoardFromString('box2', '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', 'Geonext');
board2 = JXG.JSXGraph.loadBoardFromString('box2', 'eNrtmm1v2zYQgD/bv4JAPteS7D...Y6tu7MXarPHfJ+R+tkHyx', 'Geonext');


board = JXG.JSXGraph.initBoard('box', {originX: 250, originY: 250, unitX: 50, unitY: 50});
board = JXG.JSXGraph.initBoard('box', {boundingbox: [-5, 5, 7, -3]});
// Axes
// Axes
b1axisx = board.createElement('axis', [[0,0], [1,0]], {});
b1axisx = board.createElement('axis', [[0,0], [1,0]], {});
b1axisy = board.createElement('axis', [[0,0], [0,1]], {});
b1axisy = board.createElement('axis', [[0,0], [0,1]], {});


curve = board.createElement('curve', [function(t){ return t; }, function(t){ return JXG.GetReferenceFromParameter(board2, 'A').X()*t*t+JXG.GetReferenceFromParameter(board2, 'B').X()*t+JXG.GetReferenceFromParameter(board2, 'C').X(); }, "t", -10, 10]);
curve = board.createElement('functiongraph',  
                [function(t){ return JXG.getReference(board2, 'A').X()*t*t+
                                      JXG.getReference(board2, 'B').X()*t+
                                      JXG.getReference(board2, 'C').X();  
                  },  
                  -10, 10]);
function print_table(board) {
function print_table() {
   if (hook){
   if (hook){
     $('print_a').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'A').X(),2);
     document.getElementById('print_a').value = JXG.getRef(board2, 'A').X().toFixed(2);
     $('print_b').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'B').X(),2);
     document.getElementById('print_b').value = JXG.getRef(board2, 'B').X().toFixed(2);
     $('print_c').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'C').X(),2);
     document.getElementById('print_c').value = JXG.getRef(board2, 'C').X().toFixed(2);
   }
   }
};
};
board2.addChild(board);
print_table_id = board2.addHook(print_table);
print_table_id = board2.addHook(print_table);
</source>
</source>


===GEONExT Construction used in this example===
[[Media:Sliders.gxt|Sliders.gxt]]


</html>
[[Category:Examples]]
[[Category:Calculus]]

Revision as of 15:03, 16 January 2012

This is an example for JSXGraph with two boards and so called hooks into HTML. That means the numbers below a, b, and c are updated if the points A, B, and C are dragged. And other way round, these numbers are editable.

abc

The underlying JavaScript code

<div id="box2" class='jxgbox' style="width:375px; height:150px;"></div>

<table style="border: 0px solid black; text-align: center" width="500px">
<tr>
  <th style="border: 1px solid black" width="100px">a</th>
  <th style="border: 1px solid black" width="100px">b</th>
  <th style="border: 1px solid black" width="100px">c</th>
</tr>
<tr>
  <td><input type="text" id="print_a" size="2" maxlength="7" style="border:none; text-align:right; font-size:1.2em; "
    onKeyUp="board2.getElement('A').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update();" 
    onfocus="hook=false;" onblur="hook=true"
    ></td>
  <td><input type="text" id="print_b" size="2" maxlength="7"style="border:none; text-align:right; font-size:1.2em; "
    onKeyUp="board2.getElement('B').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update();" 
    onfocus="hook=false;" onblur="hook=true
    ></td>
  <td><input type="text" id="print_c" size="2" maxlength="7" style="border:none; text-align:right; font-size:1.2em; "
    onKeyUp="board2.getElement('C').setPositionX(JXG.COORDS_BY_USER,parseFloat(this.value)); board2.update(); board.update();"
    onfocus="hook=false;" onblur="hook=true"
  ></td>
</tr>
</table>  

<div id="box" class="jxgbox" style="width:600px; height:400px;"></div>
hook = true;
board2 = JXG.JSXGraph.loadBoardFromString('box2', 'eNrtmm1v2zYQgD/bv4JAPteS7D...Y6tu7MXarPHfJ+R+tkHyx', 'Geonext');

board = JXG.JSXGraph.initBoard('box', {boundingbox: [-5, 5, 7, -3]});
// Axes
b1axisx = board.createElement('axis', [[0,0], [1,0]], {});
b1axisy = board.createElement('axis', [[0,0], [0,1]], {});

curve = board.createElement('functiongraph', 
                 [function(t){ return JXG.getReference(board2, 'A').X()*t*t+
                                      JXG.getReference(board2, 'B').X()*t+
                                      JXG.getReference(board2, 'C').X(); 
                  }, 
                  -10, 10]);						
			
function print_table() {
  if (hook){
    document.getElementById('print_a').value = JXG.getRef(board2, 'A').X().toFixed(2);
    document.getElementById('print_b').value = JXG.getRef(board2, 'B').X().toFixed(2);
    document.getElementById('print_c').value = JXG.getRef(board2, 'C').X().toFixed(2);
  }
};

board2.addChild(board);
				
print_table_id = board2.addHook(print_table);

GEONExT Construction used in this example

Sliders.gxt