RE: Regressions and the Mathematica buttons

*To*: mathgroup at smc.vnet.net*Subject*: [mg28538] RE: [mg28527] Regressions and the Mathematica buttons*From*: "David Park" <djmp at earthlink.net>*Date*: Wed, 25 Apr 2001 19:21:46 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Ian, To get your palette back, use the menu item Files -> Palettes -> BasicInput. You may also find other useful palettes there. Here is an example of a nonlinear regression. Needs["Statistics`NonlinearFit`"] This defines a function with some noise on it and makes a table of data points to use in the regression. f[x_] := Sin[x]/E^x + 0.1*Random[Real, {-1, 1}] data = Table[{x, f[x]}, {x, 0, 2, 0.02}]; plot1 = ListPlot[data]; This defines a model we will use to fit the data. The model has parameters a and b, which we are trying to determine. NonlinearRegress returns a alot of information about the regression. Among this information are a set of replacement rules for a and b called BestFitParameters. We extract these and plug them into our model to obtain the best fit function, ffit. fmodel[a_, b_][x_] := a*Sin[x]*E^(b*x); NonlinearRegress[data, fmodel[a, b][x], {x}, {a, b}] ffit[x_] = fmodel[a, b][x] /. (BestFitParameters /. %) This shows the best fit function on top of the data points. plot2 = Plot[ffit[x], {x, 0, 2}]; Show[plot1, plot2]; David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ > From: Ian Fan [mailto:ian at v-wave.com] To: mathgroup at smc.vnet.net > > Hi, I am running Mathematica 4.0 for Students and I was just wondering if > anyone could tell me how to do a regression given a list of data > to generate > a sinusodal (or for that matter, any type of) function - i.e., > how can I get > it to make a best fit graph given a set of data? Also, I made my > Mathematica > button (the one with all the quick access to the functions) disappear, can > anyone tell me how to get it back? > > Thanks in advance, > Ian Fan > >