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cb21
United Kingdom
4 Posts |
 Posted - 06/20/2017 : 5:33:14 PM
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Dear,
I try to fit XRD peaks to get the peak positions. I got some peaks which are assymetrics, some with proper shoulder (2 peaks considered) and some single peaks. I would like to use the same function but for the moment no success. The function assysigm works well for the single peak but not for the shoulder.
Pseudovoigt not ok for the assymetric here.
I don't know if assygauss or split pseudo could do it. I don't manage to set up the functions
Thank you very much
Kind regards |
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arstern
USA
237 Posts |
Posted - 06/21/2017 : 4:06:02 PM
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Hi,
If you just need to find the peak positions, please try our Quick Peaks Gadget.
Tutorial
http://www.originlab.com/doc/Tutorials/Quick-Peak-Gadget
After you have created a graph, select the Gadgets tab in the menu bar and select Quick Peaks.
With the Quick Peaks Dialog box open you can specify in the Qantities tab your Output i.e. X and Y value for peaks. Under the Find Peaks tab you can specify your peak filter i.e. find peaks with a certain height.
Hope this helps,
Aviel
OriginLab |
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cb21
United Kingdom
4 Posts |
Posted - 06/27/2017 : 04:46:37 AM
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Dear Aviel,
Thank you very much for this quick tool to get the peak position.
However, I am more looking to get the really accurate position with fitting the curve, not only the maximum of my data.
I tried with some functions but not perfect.
I would like to know if there is a predefined function of assymetric pseudo voigt 1 and assymetric gaussian. I could try these 2 functions, they will hopefully work better,
Thank you very much
Kind regards
Cyril |
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arstern
USA
237 Posts |
Posted - 06/27/2017 : 12:32:08 PM
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Hi Cyril,
Do you need the equation for the fitted curve? or just the data points of the cumulative curve and other result quantities. If you do not need the equation. I recommend using the Peak Analyzer tool. This tool will use deconvolution to fit a cumulative curve for your peaks.
Select your graph --> Select Analysis --> Select Peaks and Baseline --> Select Peak Analyzer --> Select Fit Peaks (Pro) under goals.
Please take a look at the below links for more information on the Peak Analyzer:
http://www.originlab.com/doc/Quick-Help/peak-deconvolution
http://originlab.com/doc/Origin-Help/PeakAnalyzer
Note:
1) Make sure to select Snap to Spectrum
2) You can also select Fit Control to open the Peak Fit Parameters and specify peak fit type and parameters.
Thanks,
Aviel
OriginLab
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cb21
United Kingdom
4 Posts |
Posted - 06/27/2017 : 1:47:08 PM
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Dear Aviel,
Thank you again for quick answer, really appreciate.
Yes the peak analyser tool it is really nice.
Yes I try to have the equation to fit the curve. I used initially pseudo voigt using the peak analyser tool on many peaks but unfortunately when the peak start to be assymetric it was no longer possible to use the function as it is. However it seems to be used for XRD.
I found on internet that there is a split pseudo voigt function but I don't know how to set up and maybe you have already this.
If it is possible for you I could send you one data for one peak.
Thank you really a lot for the support Aviel
Cyril |
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arstern
USA
237 Posts |
Posted - 06/27/2017 : 2:11:51 PM
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Hi Cyril,
Yes you can, please send your .opj file to tech@originlab.com.
Thanks,
Aviel
OriginLab |
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cb21
United Kingdom
4 Posts |
Posted - 06/27/2017 : 6:56:40 PM
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Dear Aviel,
Thank you very much for this, I really appreciate.
I have just sent the origin files.
Kind regards
Cyril |
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Topic |
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Fitting XRD diffractogram, peak position, issue