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ReiPa
Germany
1 Posts |
 Posted - 11/06/2015 : 06:30:04 AM
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Hi, i am using Origin 2016 (64-bit) Version b9.3.226 (Academic)
I try to fit a curve with a selfmade formula. I got a dataset of x and y values and my aim is to get with the formula :
y = L*(1-exp(-x*A))^n
the best fitting n=value.
The x- and y-values are in a table in a worksheet and the L and A values are fixed values.
I made a Scatterplot of my data and made then a nonlinear fit (Analysis-->Fitting-->Nonlinearfit)
I made an own category and an own Function with functiontype Expression. I wrote for Independent Variable x and Dependent Variable Y, Parameters are L,A,n. The function is as mentioned y = L*(1-exp(-x*A))^n
Now I want to get a curvefit, where the curve tries different n=values. It should show me the n-value-fit with the lowest R²-value. But when i press the fit button, only a fit on the line0 appears on the graph. Any help suggestions? Am I using wrong Fitting mode, or something similar?
Greetings Patrick |
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KenLefebvre
USA
66 Posts |
Posted - 11/09/2015 : 11:36:42 AM
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Hi ReiPa-
To troubleshoot this problem- I just want to check a couple things. From your statement, I'm assuming you have made this function yourself in function builder. If this is so, could you tell me what settings you gave it, such as the function model and type? Did you set it as a peak function?
Best regards,
Ken Lefebvre
Technical Service Representative
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Nonlinear fit to determine Parameter n