Problem with Curve Fitter 95% CI Upper and Lower Bounds' Equations
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Attached is a screenshot that shows the coefficients (a, b, and c) of the upper and lower 95% CI bounds are not calculated correctly.
However, the graphical representation (after activating the prediction bounds) displays a correct 95% CI. The correct equations of the 95% CI are added at the bottom in red.
For example, for the upper bound, the y-intercept is reported to be 3.55, but we can see on the graph that it is 5.28.
Does anyone know what might be the reason for that?
Torsten on 15 Sep 2023
Edited: Torsten on 15 Sep 2023
Have a read here:
It will show you the difference between confidence bounds on coefficients and prediction bounds on fits.
I guess you mean the nonsimultaneous functional bounds:
p21 = predint(fitresult,x,0.95,'functional','off')
plot(fitresult,x,y), hold on, plot(x,p21,'m--')