Re: fitting a function

*To*: mathgroup at smc.vnet.net*Subject*: [mg58339] Re: [mg58323] fitting a function*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Tue, 28 Jun 2005 21:56:38 -0400 (EDT)*Reply-to*: hanlonr at cox.net*Sender*: owner-wri-mathgroup at wolfram.com

data={{10000,.3},{15000,.5},{20000,.6},{25000,.65}}; Needs["NumericalMath`PolynomialFit`"]; p=PolynomialFit[data,3]; p[x]//Expand 6.666666666666563*^-14*x^3 - 4.999999999999937*^-9*x^2 + 0.00013333333333333212*x - 0.5999999999999929 Plot[p[x],{x,5000,30000},Epilog-> {Red, AbsolutePointSize[4],Point/@data}]; Bob Hanlon > > From: "Bosch, Darrell" <bosch at vt.edu> To: mathgroup at smc.vnet.net > Date: 2005/06/28 Tue AM 05:13:23 EDT > Subject: [mg58339] [mg58323] fitting a function > > > Dear Group, I have two questions: First, I want to fit a function > relating utility to income based on some elicited data. For example, > the following pairs might represent the income and utility values for an > individual: {10,000, .3}, {15,000, .5}, {20,000, .6}, {25,000, .65} I > want to fit the data to a function and plot the resulting function. > What is the best way to do this? PolynomialFit seems like a logical > choice, but it's not clear to me from the documentation how to specify > the command for a series of pairs of points. > > > > Second, how do I plot the resulting value of a polynomial fit in the > example below? My 'ParametricPlot' command doesn't do the job. Thanks > in advance for your help. Darrell Bosch > > > > << "NumericalMath`PolynomialFit`" > > In[28]:= > > p = PolynomialFit[{1, 4, 9, > > 16, 25, 36, 49}, 3] > > ParametricPlot[p, {p, 0, 6}, PlotRange -> All, Compiled -> True] > > > > > > Bob Hanlon Chantilly, VA