Hello, I would like to fit two lines on the curve shown in attachment, however I don't know what function in Igor Curve fit to use. My x-axis is also a timewave, would that be an issue when doing a curve fit? Thanks!
In general, you would pick a fitting function based on the theory that you think explains the data. You say "two lines" and I presume you mean "two curves", and you are probably trying to fit the obvious segments from the left to the big jump with a cluster of green points, and then from the green points to the end.
Those curves appear to my eye to be basically exponential or possibly double exponential.
If the X values are date/time, then the X values are very large and exponentials will overflow. You would need to fit with exp_XOffset or dblexp_XOffset to avoid overflow.
Since you are fitting two segments of a single wave, you would need to re-name the waves created by the fit after the first fit to avoid having the first results overwritten by the second fit.
Those curves appear to my eye to be basically exponential or possibly double exponential.
If the X values are date/time, then the X values are very large and exponentials will overflow. You would need to fit with exp_XOffset or dblexp_XOffset to avoid overflow.
Since you are fitting two segments of a single wave, you would need to re-name the waves created by the fit after the first fit to avoid having the first results overwritten by the second fit.
John Weeks
WaveMetrics, Inc.
support@wavemetrics.com
August 10, 2017 at 03:59 pm - Permalink