Hi Martina, a long time ago I also implemented a LM based program, not for a spreadsheet application, but also using functions provided as strings, not in the code.
My solution was to parse the goal function into a syntax tree and apply mathematical derivation rules on it to get syntax trees for the derivations also. Of course this only works for functions that can be derived (not everything you can find in a spreadsheet cell), but IMHO using LM for anything else doesn't make a lot of sense anyway. This way I achieved a much better accuracy and also a better performance then using e.g. approximation functions (polynomes or splines) and deriving them. Regards, Mathias Martina Fares wrote: > I calculate it with a numerical - algorithm. > Martina > > ----- Ursprüngliche Nachricht ----- > Von: Mathias Bauer <[email protected]> > Datum: Donnerstag, Oktober 1, 2009 7:24 pm > Betreff: Re: [sc-dev] Create an Extension for the Solver > An: [email protected] > > >> Martina Fares wrote: >> >> > Hello it's my again, >> > >> > I solved the problem because of the target uno-run. >> > But now I have another question: I want to create a new extension >> for the nlpsolver with the levenberg marquardt algorithm. >> > But I don't know how should I write a new extension, I know how can >> I write an new calc addin, but I don't know, how to write an extension. >> > I developed the algorithm in Java but now I want to intigrate it in >> openoffice. If I intigrate it, how should the user choose between the >> two algoritms? >> > The extension I want to develope should be similar to the actual >> extension for the NLPSolver. Or is it better if I work with the actual >> extension? >> >> Just a curious question: how do you calculate the derivations for the >> goal function that the LM algorithm requires? >> >> Regards, >> Mathias >> >> -- >> Mathias Bauer (mba) - Project Lead OpenOffice.org Writer >> OpenOffice.org Engineering at Sun: http://blogs.sun.com/GullFOSS >> Please don't reply to "[email protected]". >> I use it for the OOo lists and only rarely read other mails sent to it. >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [email protected] >> For additional commands, e-mail: [email protected] >> >> > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > -- Mathias Bauer (mba) - Project Lead OpenOffice.org Writer OpenOffice.org Engineering at Sun: http://blogs.sun.com/GullFOSS Please don't reply to "[email protected]". I use it for the OOo lists and only rarely read other mails sent to it. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
