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rainbowkoala
29 Posts |
 Posted - 04/03/2014 : 04:34:10 AM
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Origin Ver. and Service Release (Select Help-->About Origin): OriginPro 9.0.0 (32-bit)
Operating System: win7
Hello,
I hope you can help me with the following problem:
The experimental data points can be fitted with two peaks. How to get the wanted fitting result using user defined function as follows:
The symbols are experimental data points and the blue solid lines are the total #64257;tting results. The #64257;tting peak A (green line) and the #64257;tting peak B (red line) are down.
However, I can only got the fitting result as follows:
The symbols are experimental data points and the blue solid lines are the total #64257;tting results. The #64257;tting peak A (green line) and the #64257;tting peak B (red line) are down.
In orther words, I want to lower Peak A and improve Peak B.
The following are the fitting steps.
The experimental data points can be fitted with two peaks. In order to plot the two fitting peaks and the cumulative fit peak on source graph, I defined a user peak function and set parameters as in the following screenshot:
Then I used the defined fitting function to do non-linear fitting.
Select analysis:Fitting:Nonlinear Curve Fit:Open dialog:menu to bring up the NLFit dialog box. In the Function Selection part, choose the function I defined, In the Settings: Advanced: Replica: Number of Replicas part, choose 1, so the experimental data points can be fitted with two peaks, as shown in figure below:
The fiting parameters are as follow:
The original data and the detailed data in MS-Word are a little large, so I have sent them to the tech@originlab.com and quote this post.
The defined function is as follows:
y=a*sin(d*atan((x*b)^c*cos(3.14/(2*(1-c)))/(1+(x*b)^c*sin(3.14/(2*(1-c))))))/(1+2*(x*b)^c*sin(3.14/2*(1-c))+(x*b1)^(2*c))^(d/2)
In order to simplify the function, the function can also be written as follows:
y=a*sin(d*A)/(1+2*(x*b)^c*sin(3.14/2*(1-c))+(x*b1)^(2*c))^(d/2)
A= atan((x*b)^c*cos(3.14/(2*(1-c)))/(1+(x*b)^c*sin(3.14/(2*(1-c)))))
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Edited by - rainbowkoala on 04/03/2014 04:41:32 AM |
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zahraa
USA
52 Posts |
Posted - 04/03/2014 : 11:05:46 AM
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Hi,
I have emailed you from our tech account.
Thanks
Originlab Technical Representative |
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How to get the wanted fitting result