| forum.alglib.net http://forum.alglib.net/ |
|
| LSFitLinear: cubic interpolation http://forum.alglib.net/viewtopic.php?f=2&t=16 |
Page 1 of 1 |
| Author: | citydavid [ Mon May 31, 2010 10:26 pm ] |
| Post subject: | LSFitLinear: cubic interpolation |
I'm a newbie with ALGLIB I'm using a0*x^3+a1*x^2+a2*x+a3 to interpolate data values with LSFitLinear: x y 46 68 70 120 94 138 95 145 102 165 120 205 I notice wrong result and I have solved the problem scaling input by dividing by 100. What I do wrong? Regards, David |
|
| Author: | Sergey.Bochkanov [ Thu Jun 03, 2010 7:22 pm ] |
| Post subject: | Re: LSFitLinear: cubic interpolation |
Looks like your problem has very bad condition number. Scaling makes it less apparent but doesn't solve. I think that right solution is to use Chebyshev polynomials for fitting, than convert to power basis. I'll include this code in the next release of ALGLIB. |
|
| Page 1 of 1 | All times are UTC |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|