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rflesch's avatar
rflesch
Copper Contributor
Dec 30, 2024

User-Defined Fit Functions

Hello,

there are several predefined data fit functions in Excel, such as a polynomial fit – I thinks a data fit is called  a "trend line" in Excel. 

I have the following question: 

Is there a way to *define* custom fit functions, and make Excel to use those instead of the built-in ones? Is there an "add-in" or something I could use?

 

Any help would be greatly appreciated.

Thanks very much,

rflesch

 

 

  • Patrick2788's avatar
    Patrick2788
    Silver Contributor

    Yes, you can define new functions with Lambda. All we need is the algorithim or methodology and we're off.

  • If you know the mathematical algorithm you want to use. you might create a custom VBA function or procedure in the Visual Basic Editor. Details depend on what you want.

    • rflesch's avatar
      rflesch
      Copper Contributor

      Thank you – I am interested in functions such as, for example,

      y = y_0 * (1 – exp(–k*x)) + const.

      Is there a tutorial available about how to get Excel to use such a function as a fit function?

      Best Regards

      rflesch

       

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