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Re: Asking NonlinearRegression

• To: mathgroup at smc.vnet.net
• Subject: [mg88802] Re: Asking NonlinearRegression
• From: Szabolcs Horvát <szhorvat at gmail.com>
• Date: Fri, 16 May 2008 05:37:27 -0400 (EDT)
• Organization: University of Bergen
• References: <g0h4kd$la4$1@smc.vnet.net>

Navri Navri Bintang wrote:
> Hi,
> 
> I have a problem with nonlinear regression in Mathematica. I want to fit my data (below) to this following equation:
> 
> y = Exp[(1-Exp[a*(1-Exp[-b*x])])*(Exp[-b*x])/(1-Exp[-b*x])]
> 
> and I would like to find a and b values and also determined r-squared value.
> 
> I try to use NonlinearRegression/NonlinearFit code, but its not working, I hope someone could help me
> 

It is very difficult to guess what went wrong if you don't say what you 
did.  Please describe exactly how you tried to use 
NonlinearRegression/NonlinearFit, what happened (e.g. what error 
messages appeared), and what you expected to happen, then re-send the 
question to MathGroup.

I could repeat the examples that are in the documentation, but what use 
would it be?  If you asked the question here then you have already seen 
those.

Also, if you have Mathematica 5 or later, try using FindFit.


> 
> DATA:
> x	y
> 1	0.00
> 2	0.00
> 3	0.00
> 4	0.00
> 5	0.00
> 6	0.00
> 7	0.00
> 8	0.00
> 9	0.00
> 10	0.00
> 11	0.00
> 12	0.00
> 13	0.00
> 14	0.00
> 15	0.00
> 16	0.00
> 17	0.00
> 18	0.00
> 19	0.00
> 20	0.00
> 21	0.00
> 22	0.00
> 23	0.00
> 24	0.00
> 25	0.00
> 26	0.00
> 27	0.00
> 28	0.00
> 29	0.00
> 30	0.00
> 31	0.00
> 32	0.00
> 33	0.00
> 34	0.00
> 35	0.00
> 36	0.00
> 37	0.00
> 38	0.00
> 39	0.00
> 40	0.00
> 42	0.00
> 44	0.00
> 46	0.00
> 48	0.00
> 50	0.00
> 52	0.04
> 54	0.06
> 56	0.08
> 58	0.09
> 60	0.16
> 65	0.24
> 70	0.32
> 75	0.43
> 80	0.49
> 85	0.58
> 90	0.80
> 95	0.91
> 100	1.00
> 105	1
>