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nuf
Denmark
7 Posts |
 Posted - 06/14/2021 : 03:52:53 AM
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Origin Ver. and Service Release (Select Help-->About Origin): 2021b 64bit SR1
Operating System: Win 10 64bit
I have a problem with nonlinear fitting of one dataset as a function of other multiple datasets.
I try to follow the online tutorial and I seem to enter the information correct in the "Fitting Function Organizer", but once I try to perform the fitting, the setup on the screen to enter the information about my data does not match the online tutorial and apparently I enter the information wrongly.
The online tutorial is here:
https://www.originlab.com/doc/Tutorials/Fitting-Datasets
(4.2.2.8 Fitting One Dataset as a Function of Other Datasets)
Any help? |
Edited by - nuf on 06/14/2021 04:31:00 AM |
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YimingChen
1685 Posts |
Posted - 06/14/2021 : 08:48:34 AM
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Can you attach a screenshot of your NLFit dialog? You need to specify the input and output columns manually as shown in the first figure of that tutorial page. Also please check the initial values of the fitting parameters.
James |
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nuf
Denmark
7 Posts |
Posted - 06/14/2021 : 09:31:10 AM
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I have attached a number of screenshots to visualize my process. I suspect I do something wrong in the last slide where I have to enter "Input Data" because it does not look like the online tutorial.
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nuf
Denmark
7 Posts |
Posted - 06/14/2021 : 09:35:22 AM
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Here is an image of what I hope to see eventually. I have manually fitted the 4 ref spectra to obtain the "Fitted spec" as a sum of these ref spectra.
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YimingChen
1685 Posts |
Posted - 06/14/2021 : 09:58:31 AM
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In the NLFit dialog Data Selection page, can you delete the data ranges in Input Data entry. Then you should only see one Range, and within the range you need to manually specify x's and y. See figure below.
James |
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nuf
Denmark
7 Posts |
Posted - 06/14/2021 : 10:41:59 AM
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I cannot enter similar to what you enter.
I can remove the "Ranges" until one is left.
But I would like to enter "[test]test!(B,C,D,E,F)".
Or "[test]test!(B"PE",C"PC",D"APC",E"Chl-La",F"RAWSPEC")".
However, the program deletes what I enter or changes it even before I finish writing.
Also, if I try to use "Data Browser" or "Select from Worksheet" I cannot enter the text I want because there seems to be some auto-correction going on.
Could it be due to a mistake in my defined function? Or a bug in the current version of the program?
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YimingChen
1685 Posts |
Posted - 06/14/2021 : 11:01:10 AM
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I followed the steps you showed above to build the fitting function and I am also running Origin 2021b. Please see the gif. Please share with us your fitting function file (.fdf) that We can look into it.
James
quote:
Originally posted by nuf
I cannot enter similar to what you enter.
I can remove the "Ranges" until one is left.
But I would like to enter "[test]test!(B,C,D,E,F)".
Or "[test]test!(B"PE",C"PC",D"APC",E"Chl-La",F"RAWSPEC")".
However, the program deletes what I enter or changes it even before I finish writing.
Also, if I try to use "Data Browser" or "Select from Worksheet" I cannot enter the text I want because there seems to be some auto-correction going on.
Could it be due to a mistake in my defined function? Or a bug in the current version of the program?
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Edited by - YimingChen on 06/14/2021 11:01:50 AM |
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nuf
Denmark
7 Posts |
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YimingChen
1685 Posts |
Posted - 06/14/2021 : 2:49:01 PM
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For some reason when you defined the fitting parameters, Origin failed to recognize them. As you set the names to C_pe,C_pc,C_apc,C_chl. But they changed to P1, P2, P3, P4 in code builder. This doesn't happen on my PC. Do you remember if you manually change the parameter names?
Can you also try define the function again and see if it can be reproduced.
James |
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nuf
Denmark
7 Posts |
Posted - 06/14/2021 : 3:18:31 PM
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I don't know how the P1, P2, P3, P4 names came about. I did not enter them. Maybe it is the default names and the program does not like my names.
Here is what I did next:
I have made a new function where I use the same formula but different names, so the outcome should be the same.
I use s1, s2, s3, s4 for my reference spectra, and P1, P2, P3, P4 for parameter names.
I set 0<=P<=3 for all parameters.
And then it worked beautifully. Maybe there is a bug in the program with respect to understanding names with underscore. In any case, I can live with the default parameter names.
Thanks for your help!
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nuf
Denmark
7 Posts |
Posted - 06/14/2021 : 3:22:54 PM
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| Oh, and I also removed a hyphen in one of the column names. |
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Topic |
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Fitting one dataset as funct. of multiple datasets