Problem with function definition inside DynamicModule

*To*: mathgroup at smc.vnet.net*Subject*: [mg130344] Problem with function definition inside DynamicModule*From*: "Kevin J. McCann" <kjm at KevinMcCann.com>*Date*: Wed, 3 Apr 2013 22:52:17 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net

I am trying to write a dynamic module that does a polynomial fit with different orders of the polynomial. I define f[x], the fit within the module, but it does not update. If I try a delayed equals in the definition, I get lots of unpleasant error messages. Any help would be appreciated. Thanks, Kevin data = Table[{x, x^2 + RandomReal[{-1, 1}]}, {x, 0, 5}]; datafit[dat_?ListQ] := DynamicModule[{m, d, f, x, y, k, n = 1, p1, powers}, p1 = ListPlot[dat, Joined -> False, PlotStyle -> {Red, AbsolutePointSize[7]}, PlotRange -> All]; (* Here is where I think the problem is *) f[x_] = Fit[dat, Table[x^k, {k, 0, n}], x]; Panel[ Column[ { Row[{"n", Spacer[5], SetterBar[Dynamic[n], Range[5]]}], Dynamic@ Plot[f[x], {x, 0, 5}, Epilog -> p1[[1]], PlotLabel -> "n = " <> ToString[n], PlotRange -> {0, 30}] } ](*Column*) ](*Panel*) ] datafit[data]