Re: How to use BestFitParameters?

*To*: mathgroup at smc.vnet.net*Subject*: [mg24283] Re: [mg24274] How to use BestFitParameters?*From*: BobHanlon at aol.com*Date*: Fri, 7 Jul 2000 00:11:25 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

In a message dated 7/5/2000 11:39:23 PM, piovere at pdq.net writes: >p is a list of data pairs { {x1,y1}, {x2,y2}, ....} and when I fit >this data to a function Mathematica does a pretty good job of doing the >fit: > >NonlinearRegress[p, a/Sqrt[d^2 + (x1 - w0)^2], {x1}, {a, d, w0}, > MaxIterations -> 200, RegressionReport -> BestFitParameters] > >gives this as an output: >{BestFitParameters -> {a -> 1.07061, d -> 0.300272, w0 -> 28.8068}} > >I know it is pretty a pretty good fit to the data because I can use >another program like Excel to plot the curve using these parameters >and display it next to the data. It sure would be nice to do this in >Mathematica without going to an outside program. I've tried things but >I >can't seem to be able to get to the parameters a, d and w0. I can't >even list them. For example, I'd like to display the number >d/Sqrt[w0^2-d^2]. So I tried this: > >d/Sqrt[w0^2-d^2] /. % > >All I get is the formula in symbolic form. > >Can someone here provide some relief? > d/Sqrt[w0^2-d^2] /. (BestFitParameters /. %) Bob Hanlon