Least-squares line fitting: Difference between revisions
From JSXGraph Wiki
A WASSERMANN (talk | contribs) No edit summary |
A WASSERMANN (talk | contribs) No edit summary |
||
| Line 6: | Line 6: | ||
<jsxgraph width="600" height="600"> | <jsxgraph width="600" height="600"> | ||
var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-5,5,5,-5], keepaspectratio:true, axis:true}); | var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-5,5,5,-5], keepaspectratio:true, axis:true}); | ||
var i, p = [], angle, xr, yr, delta = | var i, p = [], angle, xr, yr, delta = 0.1; | ||
// Random points are constructed which lie roughly on a line | // Random points are constructed which lie roughly on a line | ||
| Line 14: | Line 14: | ||
brd.suspendUpdate(); | brd.suspendUpdate(); | ||
for (i=0;i<5;i++) { | for (i=0;i<5;i++) { | ||
yr = 10*(Math.random()-0.5); | |||
xr = 0.*xr+delta*(Math.random()-0.5) +1.0; | |||
p.push(brd.create('point',[xr, yr], {withLabel:false})); | p.push(brd.create('point',[xr, yr], {withLabel:false})); | ||
} | } | ||
Revision as of 11:15, 7 November 2010
This little JXSGraph application finds the line - described by homogeneous coordinates [a,b,c] - that minimizes
- [math]\displaystyle{ \sum_{i=1}^n (ax_i+by_i+cz_i)^2. }[/math]
Coming soon...
