Re: NonlinearFit
- To: mathgroup at smc.vnet.net
- Subject: [mg42149] Re: NonlinearFit
- From: Bill Rowe <listuser at earthlink.net>
- Date: Fri, 20 Jun 2003 04:57:46 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On 6/19/03 at 3:59 AM, civnrn at hotmail.com (Rees) wrote:
> Please could someone assist me in curve fitting.
> I have the following x,y data
> data = {{0.1,0.113387476}, {0.2, 0.194633152}, {0.3,
> 0.252848224}, {0.4, 0.294561145}, {0.5,
> 0.324449759}, {0.6, 0.345865887}, {0.7,
> 0.361211213}, {0.8, 0.37220662}, {0.9,
> 0.380085173}, {1.0, 0.385730403}};
> Now I wish to fit an exponential curve of the form below to it:
>
> c*[1-Exp(-3x/a]
> where c and a are parameters to be determined.
> I tried the following but it doesn't work:
> NonlinearFit[data, c*(1 - Exp(-3*x1/a)), {x1}, {c, a}]
Your syntax for the model is incorrect. It should be c*(1 - Exp[-3*x1/a]). Notice where I've replace parantheses with square brackets