Help with fitting

*To*: mathgroup at smc.vnet.net*Subject*: [mg131494] Help with fitting*From*: ismail <ism45 at yahoo.com>*Date*: Fri, 9 Aug 2013 01:48:47 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net

Hello, I have experimental data with (y) and (x) I need to fit them into the following model Log (y/b) = Log (ax /b/1+ax/b) + (-0.22/1+(log ax/b)^2) The result should be a plot with Log y on the y-axis, Log x in the x axis. and the two constants a and b will be the result of the fitting. I tried that in Mathematica, but my problem is that I don't know how to define the function so I can keep (Logy/b) in the left side. Mathematica allows me only to defin a model in the form (y=f(x)) Any help please?

**Follow-Ups**:**Re: Help with fitting***From:*Bob Hanlon <hanlonr357@gmail.com>