Differential equations: Difference between revisions

Revision as of 09:30, 14 July 2010

@@ Line 3: / Line 3: @@
 var P = brd.create('point',[0,0], {name:'x_0'});
 var f = function(t,x) {
-        return 3*x;
+        return [3*x[0]];
      };
 function ode() {
-   var I = [0, 25];
+    var data = JXG.Math.Numerics.rungeKutta(JXG.Math.Numerics.predefinedButcher.Heun, [1], [0, 2], 20, f);
-   var N = 1000;
+}
-   var x0 = P.Y();
-    var data = JXG.Math.Numerics.rungeKutta(JXG.Math.Numerics.predefinedButcher.Euler, x0, I, N, f);
-   var t = [];
-   var q = I[0];
-   var h = (I[1]-I[0])/N;
-   for(var i=0; i<data.length; i++) {
-      data[i].push(q);
-      q += h;
-   }
-   return data;
-};
 var g = brd.createElement('curve', [[0],[0]], {strokeColor:'red', strokeWidth:'2px'});
 g.updateDataArray = function() {
      var data = ode();
+    var h = 0.1;
      this.dataX = [];
      this.dataY = [];
      for(var i=0; i<data.length; i++) {
-         this.dataX[i] = data[i][2];
+         this.dataX[i] = i*h;
          this.dataY[i] = data[i][0];
      }