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November 09, 2010


Fred Katz


After you have a rough solution, list all of the points vertically on a spreadsheet and use Excel to find the standard deviation between the equation fit and the actual points. Write the equation with each of the exponents as individual cells. Tweak each cell value trying to minimize the sum of the standard deviations. This will give you a tighter fit.

Fred Katz

Ray Keefe

Hi John,

nice method. A pity about the iteration but that is often the way of these things.

I assume this method relies on the data being at uniform x axis intervals?

And I'm always interested in useful spreadsheet examples so I'd like to take you up on you offer and get a copy.

Thanks for a useful post

Ray Keefe
Successful Endeavours Pty Ltd
Casey Business of the Year 2010
Award Winning Electronics Design and Embedded Software Development

John D.

Hi, Ray.

The intervals for "x" don't bneed to be evenly spaced. The x-values can be chosen arbitrarily.

I will e-mail the spreadsheet to you in just a little while.


Jim Anderson

Hi Don,

I would appreciate a copy of the spreadsheet also.

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