Parabola: Difference between revisions

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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.
<html>
<html>
<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
<link rel="stylesheet" type="text/css" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css" />
Line 39: Line 42:
print_table_id = board2.addHook(print_table);
print_table_id = board2.addHook(print_table);
</script>
</script>
</html>
===The underlying JavaScript code===
<source lang="html4strict">
<div id="box" class="jxgbox" style="width:600px; height:400px;"></div>
<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>
  <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> 
</source>


<source lang="javascript">
hook = true;
board2 = JXG.JSXGraph.loadBoardFromString('box2', 'eNrtmm1v2zYQgD/bv4JAPteS7D...Y6tu7MXarPHfJ+R+tkHyx', 'Geonext');
board = JXG.JSXGraph.initBoard('box', {originX: 250, originY: 250, unitX: 50, unitY: 50});
// Axes
b1axisx = board.createElement('axis', [[0,0], [1,0]], {});
b1axisy = board.createElement('axis', [[0,0], [0,1]], {});


</html>
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]);
function print_table(board) {
  if (hook){
    $('print_a').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'A').X(),2);
    $('print_b').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'B').X(),2);
    $('print_c').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'C').X(),2);
  }
};
print_table_id = board2.addHook(print_table);
</source>
 
[[Category:Examples]]

Revision as of 16:44, 3 January 2009

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="box" class="jxgbox" style="width:600px; height:400px;"></div>
<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>
  <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>
hook = true;
board2 = JXG.JSXGraph.loadBoardFromString('box2', 'eNrtmm1v2zYQgD/bv4JAPteS7D...Y6tu7MXarPHfJ+R+tkHyx', 'Geonext');
board = JXG.JSXGraph.initBoard('box', {originX: 250, originY: 250, unitX: 50, unitY: 50});
// Axes
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]);						
			
function print_table(board) {
  if (hook){
    $('print_a').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'A').X(),2);
    $('print_b').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'B').X(),2);
    $('print_c').value = board.algebra.round(JXG.GetReferenceFromParameter(board, 'C').X(),2);
  }
};
				
print_table_id = board2.addHook(print_table);