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ABFoster
United Kingdom
4 Posts |
 Posted - 01/27/2014 : 05:59:25 AM
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I have completed some multiple Gaussian fitting in Peak Analyser.
The peak on the left of the image requires an asymmetric Gaussian fit, which I have completed seperately using AsymmetricGauss in User Defined.
How do I bring the fits together to create an overall cumulative fit graph of the spectrum? It does not allow me to do it in Peak Analyser.
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lkb0221
China
497 Posts |
Posted - 01/27/2014 : 10:13:22 AM
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Hi, Andrew
If you are using Origin version higher than 8.0, you can specify each peak's fitting function in Peak Analyzer, and no need to fit separately.
To change a peak's function, in "Fit Peaks" step in Peak Analyzer, click the "Fit Control" button at the bottom of the dialog to open "Peak Fit Parameters" dialog. Click the "Peak Type" cell of the peak you want to customize, and select the function. Then do the fit.
So in the former "Find Peaks" step, you would need to change your settings to find all the peaks.
Please read the following page for more details of Peak Fit Parameters dialog
http://www.originlab.com/doc/Origin-Help/PeakAnalyzer-FitPara-Dialog
Zheng
OriginLab |
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zahraa
USA
52 Posts |
Posted - 01/27/2014 : 10:56:06 AM
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Hi,
For asymmetric Gaussian you may also be able to use the Bigaussian built in function. http://www.originlab.com/www/helponline/origin/en/UserGuide/Bigaussian.html
I hope you don't mind but I used the digitizer to duplicate your curve and fit using Big Gaussian on the peak on the left and and Gaussian for peaks on the right, this is the Fit Control dialog:
I came up with the following:
I did not use as many peaks as you did for the peaks on the right but this is the general fit I got for the curve. Hope it helps
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Edited by - zahraa on 01/27/2014 11:10:44 AM |
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ABFoster
United Kingdom
4 Posts |
Posted - 01/27/2014 : 11:09:09 AM
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I am using Origin 8.5. Have tried that. The AsymmetricGauss was not originally in the list of peak types available. I shared it across into the correct folder. When I select the one peak to be analysed via AsymmetricGauss, the fit button is greyed out not allowing analysis.
The error message going back to previous screen is 'AsymmetricGauss is not a peak function. It has no parameters.'
quote:
Originally posted by lkb0221
Hi, Andrew
If you are using Origin version higher than 8.0, you can specify each peak's fitting function in Peak Analyzer, and no need to fit separately.
To change a peak's function, in "Fit Peaks" step in Peak Analyzer, click the "Fit Control" button at the bottom of the dialog to open "Peak Fit Parameters" dialog. Click the "Peak Type" cell of the peak you want to customize, and select the function. Then do the fit.
So in the former "Find Peaks" step, you would need to change your settings to find all the peaks.
Please read the following page for more details of Peak Fit Parameters dialog
http://www.originlab.com/doc/Origin-Help/PeakAnalyzer-FitPara-Dialog
Zheng
OriginLab
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ABFoster
United Kingdom
4 Posts |
Posted - 01/27/2014 : 11:12:16 AM
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Thanks, will try this approach instead.
quote:
Originally posted by zahraa
Hi,
For asymmetric Gaussian you may also be able to use the Bigaussian built in function. http://www.originlab.com/www/helponline/origin/en/UserGuide/Bigaussian.html
I hope you don't mind but I used the digitizer to duplicate your curve and fit using Big Gaussian on the peak on the left and and Gaussian for peaks on the right, this is the Fit Control dialog:
I came up with the following:
I did not use as many peaks as you did for the peaks on the right but this is the general fit I got for the curve. Hope it helps
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ABFoster
United Kingdom
4 Posts |
Posted - 01/27/2014 : 11:25:40 AM
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Yes, using BiGaussian works fine. See image. Thanks for your help.
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zahraa
USA
52 Posts |
Posted - 01/27/2014 : 11:50:51 AM
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Hi
I'm glad that worked. Just a side note, if the AsymmetricGauss function you are referring to here is a user defined one, the reason that it was grayed out and giving you that error might be because you did not specify it was a Peak Function when you were building it in the Fitting Function Builder. In order to specify a user defined function as a peak function you have to check this box:
Then you save it in the PFW category as you mentioned you did and it can be used in the Peak Analyzer.
quote:
Originally posted by ABFoster
I am using Origin 8.5. Have tried that. The AsymmetricGauss was not originally in the list of peak types available. I shared it across into the correct folder. When I select the one peak to be analysed via AsymmetricGauss, the fit button is greyed out not allowing analysis.
The error message going back to previous screen is 'AsymmetricGauss is not a peak function. It has no parameters.'
Thanks! |
Edited by - zahraa on 01/27/2014 11:53:16 AM |
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Topic |
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Obtaining cumulative fitting graph