Least-squares line fitting: Difference between revisions

Revision as of 19:39, 5 November 2010

This little JXSGraph application finds the line - described by homogeneous coordinates [a,b,1] - that minimizes

[math]\displaystyle{ \sum_{i=1}^n (a_ix_i+b_iy_i+1)^2. }[/math]

@@ Line 1: / Line 1: @@
+This little JXSGraph application finds the line - described by homogeneous coordinates [a,b,1] - that minimizes
+:<math> \sum_{i=1}^n (a_ix_i+b_iy_i+1)^2.</math>
 <jsxgraph width="600" height="600">
 var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-5,5,5,-5], keepaspectratio:true});
@@ Line 8: / Line 12: @@
 // points from the line.
 brd.suspendUpdate();
-for (i=0;i<3;i++) {
+for (i=0;i<1000;i++) {
    xr = 10*(Math.random()-0.5);
    yr = 0.3*xr+delta*(Math.random()-0.5) +1.0;