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Who find a better fit of this experimental data?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg45609] Who find a better fit of this experimental data?
  • From: guillerm at aida.usal.es (Guillermo Sanchez)
  • Date: Fri, 16 Jan 2004 06:05:27 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

Dear group?. 
I attach some expemental data. I have fitted them with a biexponential
function, but the fit is not good enough. Who find a better fit of
this experimental data?

Needs["Statistics`NonlinearFit`"];

data = {{0.0, 3.048}, {0.05, 286.435}, {0.10, 534.718}, {0.15,
370.241}, {0.20, 240.302`}, {0.25, 170.005`}, {0.30, 128.6}, {0.35,
84.36}, {0.40,
66.58}, {0.45`, 52.32}, {0.50`, 40.30`}, {0.55, 28.78`}, {0.60,
20.75}, {0.65, 16.226`}, {0.70, 14.19`}, {0.75, 13.14`}, {0.80,
10.63`}, {0.85, 7.57`}, {0.90, 7.414`}, {0.95, 5.026`}, {1.00, 3.69`},
{1.05, 4.39`}, {1.10, 3.17`},
{1.15, 3.16`}, {1.20, 2.55`}, {1.25, 2.334`}, {1.30`, 2.164`}, {1.35,
2.1`}, {1.40, 1.63`}, {1.45, 1.445`}, {1.50, 0.513`}, {1.55, 1.14`},
{1.60, 0.852`}, {1.65, 0.761`}, {1.70, 0.734`}, {1.75, 0.775`}, {1.80,
0.473`}, {1.85, 0.389`}, {1.90, 0.514`}, {1.9767 , 0.347`}, {2.077,
0.274`}, {2.177 , 0.14`}, {2.277, 0.088`}, {2.377, 0.013}};

f1[t_] := a1 Exp[b1 t] + a2  Exp[b2 t];

NonlinearRegress[data, f1[t], {t}, { {a1 , 10000}, {a2 , 10000}, { b1,
-9}, {b2, -11}}, MaxIterations -> 100][[1]]


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