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ljc7352489
USA
1 Posts |
 Posted - 01/16/2019 : 4:02:14 PM
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Origin Ver. and Service Release (Select Help-->About Origin):
Operating System:
Hi,
I defined my curve fitting function: y=(((1+((2*pi*x*T)^A)*sin(A*pi/2))^2+(((2*pi*x*T)^A)*cos(A*pi/2))^2)^(-B/2))*E*cos(B*(arctan(((2*pi*x*T)^A)*cos(A*pi/2)/(1+((2*pi*x*T)^A)*sin(A*pi/2)))))+Ein+A0*(2*pi*x)^(-n)
with fitting parameters: A,B,T,A0,n,E, and constant: Ein(I set to 2.1), I chose initial values as close as possible. But the fitting does not converge, even after fixing several of the parameters.
I really appreciate any form of help. Thanks. |
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JacquelineHe
287 Posts |
Posted - 01/17/2019 : 02:40:51 AM
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Hi,
According to your description, I am not sure whether the initial values lead fitting not converge.
You can refer to this Quick help page to check the reason:
https://www.originlab.com/doc/Origin-Help/The_Reason_Why_Fail_to_Converge
If you still can not find the reason, could you mind to send your Project file(.OPJ / .OPJU) and User defined function file( .FDF) to our Tech Support department <tech@originlab.com>, then we can check the issue on our machine?
Please tell us your detailed version and Serial Number information, when you send the email. You can check these information by selecting "Help: About Origin" in the menu.
Thanks
Jacqueline
Originlab
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Custom Function Curve Fitting(Need help!)