diff -r d59bea55db9b -r c445c931472f examples/qfit.mod --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/examples/qfit.mod Mon Dec 06 13:09:21 2010 +0100 @@ -0,0 +1,49 @@ +/*Quadratic Curve Fitting Solution + + Find a plausable quadratic fit to a sample of points + + Nigel_Galloway@operamail.com + February 1st., 2009 +*/ +set Sample; +param Sx {z in Sample}; +param Sy {z in Sample}; + +var a; +var b; +var c; + +equalz1 :sum{z in Sample} a*Sx[z]*Sx[z]*Sx[z]*Sx[z] + sum{z in Sample} b*Sx[z]*Sx[z]*Sx[z] + sum{z in Sample} c*Sx[z]*Sx[z] = sum{z in Sample} Sy[z]*Sx[z]*Sx[z]; +equalz2 :sum{z in Sample} a*Sx[z]*Sx[z]*Sx[z] + sum{z in Sample} b*Sx[z]*Sx[z] + sum{z in Sample} c*Sx[z] = sum{z in Sample} Sy[z]*Sx[z]; +equalz3 :sum{z in Sample} a*Sx[z]*Sx[z] + sum{z in Sample} b*Sx[z] + sum{z in Sample} c = sum{z in Sample} Sy[z]; + +solve; + +printf "\nbest quadratic fit is:\n\ty = %f %s %fx %s %fx^2\n\n", c, if b < 0 then "-" else "+", abs(b), if a < 0 then "-" else "+", abs(a); + +data; + +param: +Sample: Sx Sy := + 1 0 1 + 2 0.5 0.9 + 3 1 0.7 + 4 1.5 1.5 + 5 1.9 2 + 6 2.5 2.4 + 7 3 3.2 + 8 3.5 2 + 9 4 2.7 + 10 4.5 3.5 + 11 5 1 + 12 5.5 4 + 13 6 3.6 + 14 6.6 2.7 + 15 7 5.7 + 16 7.6 4.6 + 17 8.5 6 + 18 9 6.8 + 19 10 7.3 +; + +end;