Even simpler function plotter: Difference between revisions

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(New page: <html> <input type="text" id="input" value="sin(x)*x"> <input type="button" value="plot" onClick="plotter()"> </form> <jsxgraph width="600" height="400"> var board = JXG.JSXGraph.initBoard...)
 
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<input type="text" id="input" value="sin(x)*x">
<input type="text" id="input" value="sin(x)*x">
<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="add slope info" onClick="addSlopeInfo()">
<input type="button" value="add tangent" onClick="addTangent()">
<input type="button" value="add Derivative" onClick="addDerivative()">
</form>
</form>
</html>
<jsxgraph width="600" height="400">
<jsxgraph width="600" height="400">
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 t = board.algebra.geonext2JS(document.getElementById('input').value);
   var txtraw = document.getElementById('input').value;
  var f = new Function('x','var y = '+t+'; return y;');
  f = board.jc.snippet(txtraw, true, 'x', true);
  board.create('functiongraph',[f]);
  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];
                }
              ],{name:txtraw, withLabel:true});
}
 
function clearAll() {
    JXG.JSXGraph.freeBoard(board);
    board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true});
    f = null;
    curve = null;
}
 
function addSlopeInfo() {
    if (JXG.isFunction(f)) {
        var txtraw = document.getElementById('input').value;
        board.suspendUpdate();
        var q = board.create('glider', [2, 1, curve], {withLabel:false});
        var t = board.create('text', [
          function(){ return q.X()+0.1; },
          function(){ return q.Y()+0.1; },
          function(){ return "The slope of the function f(x)=" + txtraw + "<br>at x=" + q.X().toFixed(2) + " is equal to " + (JXG.Math.Numerics.D(f))(q.X()).toFixed(2); }
      ],
      {fontSize:15});
        board.unsuspendUpdate();
    }
}
 
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});
    }
}
}
</jsxgraph>
</jsxgraph>
===The underlying JavaScript code===
<source lang="html4strict">
<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()">
</source>
<source lang="javascript">
var board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true});
var f, curve; // global objects
function plotter() {
  var txtraw = document.getElementById('input').value;
  f = board.jc.snippet(txtraw, true, 'x', true);
  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];
                }
              ],{name:txtraw, withLabel:true});
  var q = board.create('glider', [2, 1, curve], {withLabel:false});
  var t = board.create('text', [
          function(){ return q.X()+0.1; },
          function(){ return q.Y()+0.1; },
          function(){ return "The slope of the function f(x)=" + txtraw + "<br>at x=" + q.X().toFixed(2) + " is equal to " + (JXG.Math.Numerics.D(f))(q.X()).toFixed(2); }
      ],
      {fontSize:15});
}
function clearAll() {
    JXG.JSXGraph.freeBoard(board);
    board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true});
    f = null;
    curve = null;
}
function addSlopeInfo() {
    if (JXG.isFunction(f)) {
        var txtraw = document.getElementById('input').value;
        board.suspendUpdate();
        var q = board.create('glider', [2, 1, curve], {withLabel:false});
        var t = board.create('text', [
          function(){ return q.X()+0.1; },
          function(){ return q.Y()+0.1; },
          function(){ return "The slope of the function f(x)=" + txtraw + "<br>at x=" + q.X().toFixed(2) + " is equal to " + (JXG.Math.Numerics.D(f))(q.X()).toFixed(2); }
      ],
      {fontSize:15});
        board.unsuspendUpdate();
    }
}
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>
[[Category:Examples]]
[[Category:Calculus]]

Latest revision as of 10:58, 21 January 2019

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 txtraw = document.getElementById('input').value;
  f = board.jc.snippet(txtraw, true, 'x', true);
  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];
                }
              ],{name:txtraw, withLabel:true});
  var q = board.create('glider', [2, 1, curve], {withLabel:false});
  var t = board.create('text', [
          function(){ return q.X()+0.1; },
          function(){ return q.Y()+0.1; },
          function(){ return "The slope of the function f(x)=" + txtraw + "<br>at x=" + q.X().toFixed(2) + " is equal to " + (JXG.Math.Numerics.D(f))(q.X()).toFixed(2); }
      ], 
      {fontSize:15});
}

function clearAll() {
    JXG.JSXGraph.freeBoard(board);
    board = JXG.JSXGraph.initBoard('jxgbox', {boundingbox:[-5,8,8,-5], axis:true});
    f = null;
    curve = null;
}

function addSlopeInfo() {
    if (JXG.isFunction(f)) {
        var txtraw = document.getElementById('input').value;
        board.suspendUpdate();
        var q = board.create('glider', [2, 1, curve], {withLabel:false});
        var t = board.create('text', [
          function(){ return q.X()+0.1; },
          function(){ return q.Y()+0.1; },
          function(){ return "The slope of the function f(x)=" + txtraw + "<br>at x=" + q.X().toFixed(2) + " is equal to " + (JXG.Math.Numerics.D(f))(q.X()).toFixed(2); }
      ], 
      {fontSize:15});
        board.unsuspendUpdate();
    }
}

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});
    }
}