I would like to fit a function of the form: $a \log(b x)$ to a set of data:
data = {{10, 10/153}, {100, 100/1833}, {200, 200/3814}, {300, 300/5847}, {500, 500/10006},
{625, 625/12649}}
The input string to WolframAlpha:
"log fit {{10, N[10/153,16]},{100,N[100/1833,16]},{200,N[200/3814,16]},{300,N[300/5847,16]},{500,N[500/10006,16]},{625,N[625/12649,16]}}"
produces a nice logarithmic fit of this data. However, using FindFit
with my copy of Mathematica 7.0 produces nonsensical values for $(a,b)$ and/or complex functions. How did WolframAlpha produce this fit, and how might I find this fit using my copy of Mathematica?