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Where does my (small) notebook go wrong?

  1. Mar 1, 2010 #1
    Hi all,

    A few days ago I have done an experiment with a spectroscope to find the value of Rydberg's constant. In my notebook I have a dataset that I want to use a NonLinearModelFit on to find this constant. However, it will not work and I just can't figure out why it won't. I have gotten rid of everything else in the notebook to keep it as clear as possible:

    View attachment Notebook1.nb

    Could anyone please take a look?
  2. jcsd
  3. Mar 2, 2010 #2


    User Avatar
    Gold Member

    I think the problem is all in your starting points. Do you have a better starting point for "p" than one?
    I see that {p,0} or {p,0.027} works:
    Code (Text):

    fit3 = NonlinearModelFit[
      dat1, \[Theta]nul + \[Alpha] + (ArcSin[p k - Sin[\[Alpha]]]), {{p,
        0}, {\[Theta]nul, 3.15}, {\[Alpha], 0.}}, k, Weights -> wt]
  4. Mar 2, 2010 #3
    Thanks a bunch, that works indeed!
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