script/tutorial/66_WeightedPolynomialFit.js

@@ -0,0 +1,41 @@
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// Example if fitting with weights
+/////////////////////////////////////////////////////////////////////////////////////////////////// 
+
+
+run("mathutils")
+run("plotutils")
+
+
+fx = [ 1.0,  2.0,   3.0,   4.0,   5.0,   6.0,   7.0,   8.0,   9.0,  10.0]
+fy = [36.0, 66.0, 121.0, 183.0, 263.0, 365.0, 473.0, 603.0, 753.0, 917.0]
+num_samples = fx.length
+
+p=plot(fy, "Observed Data", xdata=fx)[0]
+p.setLegendVisible(true)
+
+pars_polynomial=  fit_polynomial(fy, fx, 1, null)
+func = new PolynomialFunction(pars_polynomial)
+plot_function(p, func, "1st order", fx)
+
+var w = []; size=num_samples; while(size--) w.push(1.0);
+w[5]=20.0 
+pars_polynomial=  fit_polynomial(fy, fx, 1, null, w)
+func = new PolynomialFunction(pars_polynomial)
+plot_function(p, func, "1st order Weighted: " + w , fx)
+    
+pars_polynomial=  fit_polynomial(fy, fx, 2, null, w)
+func = new PolynomialFunction(pars_polynomial)
+plot_function(p, func, "2nd order" + w , fx)
+for (var xp in fx){
+    print (fx[xp] + " " + poly(fx[xp], pars_polynomial))
+}
+
+print ("")
+w = [ 10.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 10.0] 
+pars_polynomial=  fit_polynomial(fy, fx, 2, null, w)
+func = new PolynomialFunction(pars_polynomial)
+plot_function(p, func, "2n order Weighted: " + w , fx)
+for (var xp in fx){
+    print (fx[xp] + " " + poly(fx[xp], pars_polynomial))
+}