Re: How to find the best fit for a list {x,y} of data
- To: mathgroup at smc.vnet.net
- Subject: [mg91933] Re: How to find the best fit for a list {x,y} of data
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Sat, 13 Sep 2008 05:55:09 -0400 (EDT)
- Organization: Uni Leipzig
- References: <gadcid$rh2$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
Hi,
and how can we know what do you understand as
"best fit to my data" ?
Regards
Jens
dinodeblasio at gmail.com wrote:
> Hello everybody,
> I have the list and the y=f(x) equation
>
> data = {{1, 1}, {28, 0.719188377}, {54, 0.35746493}, {81,
> 0.182114228}, {117, 0.166082164}, {260, 0.132765531}};
> express = (1 - k*x)*(1 - k*x/q)*(1 - p*k*x/q)
>
> (1 - k x) (1 - (k x)/q) (1 - (k p x)/q)
>
>
> "k,q and p are parameters; then I do the fitting":
>
> f1 = FindFit[data, (1 - k*x)*(1 - k*x/q)*(1 - p*k*x/q), {{k, 0.01},
> {p, 1.5}, {q,1}}, x, MaxIterations -> 200]
>
> "and I obtain":
>
> {k -> 0.00586032, p -> 2.86841, q -> 2.86841}
>
> "My question is: how I can find the best fit to my data for values of
> (k,q,p) >0" ??
>
> Thank you very much for your help.
> Dino
>