Re: Fitting part of a List

*To*: mathgroup at smc.vnet.net*Subject*: [mg127527] Re: Fitting part of a List*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Wed, 1 Aug 2012 04:57:51 -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

On 7/30/12 at 10:14 PM, eppi2.0 at freenet.de (Butterfly87) wrote: >I have a set of data(63 pairs) of the form {x-Value, Intensity} >imported to Mathematica. I also managed to extract the data pairs 5 >to 25 using the Take-function. I want to fit these data using the >Fitfunction TS[q] and FindFit. I told Mathematica to follow this >Input: FindFit[d2[q], TS[q], {{a, 1000}, {b, 1500}, {c, 0.008}}, q] You are using q for two distinct purposes: 1) as the independent variable for your model TS[q] 2) as a known parameter to select a portion of your data d2[q] You cannot use q for both of these purposes in a single call to FindFit. Also, be aware ds2[q] is the function evaluated at q, not a selection for a subset of your data. It is possible to use the notation ds2[q] as a subscripted variable. But unless you data is different than what you seem to be describing (an n x 2 array), even if you use this correctly as a subscripted variable you would be choosing a single data point which clearly won't work.