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Leonardo C
Italy
3 Posts |
 Posted - 02/16/2022 : 09:55:34 AM
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Hello to everybody,
I am just beginning to use Origin, so I apologize if my question will be trivial.
I often work on multivariate analysis of spectroscopic data. In these analysis spectra are arranged as row of a matrix, where each column is a variable (wavelength) and each row is an observation.
Therefore I would need a way for plotting datasheets row-wise instead of column-wise. I have looked at available tutorials, but I have found nothing about it yet.
Alternatively, is there a way for transponsing the datasheet in Origin. Or should I transponse then before importation.
Thanks in advance for help.
Leonardo C |
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snowli
USA
1379 Posts |
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Leonardo C
Italy
3 Posts |
Posted - 02/21/2022 : 05:13:52 AM
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Hello snowli,
thans for your help. I followed your advice and was able to do my first row-wise plot. I have also seen that row plotting produce a new sheet where all spectra are transponsed column-wise. This is nice for further spectra processing because, for example, the derivative tool in Origin acts column-wise (at least I have not found an option for choosing the direction along which to differentiate).
I have, however, two new problems.
I have tried to select more spectra and calculate their 1st derivative but, apparently, Origin processes just the first column ignoring the others. Processing one spectra at a time would be very awkward. How can I derivate (or, more generally, manipulate) more spectra simultaneously?
The second problem is this. Suppose I have got my matrix of derivative spectra and want to carry out a multivarate statistical analysis (PCA, PLS of a classification). I would need to turn the row-wise again. How could i do it?
Kind regards.
Leonardo C |
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snowli
USA
1379 Posts |
Posted - 02/21/2022 : 10:43:13 AM
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Hi Leonardo,
You may have noticed not all our tools supports multiple input.
But after u can single click the green lock and choose Repeat this for All Y Columns (last entry) to get derivative of all other Ys after the processed one.
I am not sure about your PCA question. After getting all derivatives of each spectrum in a column, they are like a matrix too. Do you mean u can do PCA with it?
Thanks, Snow |
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Leonardo C
Italy
3 Posts |
Posted - 02/25/2022 : 08:29:24 AM
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Dear Snow,
I have not well understood how to use the "outpute mode" indicators in the derivative dialog box.
If I add the derivative as a new column in the worksheet the option "repeate for all Y columns" is not active (it seems logic to me, otherwise the software would enter in an infinite loop).
On the other hand, if I creates the derivative as a new sheet and launch the "repeat" operation, Origin creates a new two-column sheet for each spectrum (66 spectra!).
I would like to create a single sheet, having the same size of the original one, but with derivative spectra instead of original ones. How can I do?
Best regards.
Leonardo C |
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ChaoC
USA
165 Posts |
Posted - 02/25/2022 : 10:23:24 AM
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Hi Leonardo,
Origin can recognize that the new columns have already had the differentiate operation performed on them and will exclude those columns. This avoids entering an infinite loop.
To create a second sheet the same size as the first one but with derivative spectra you can do the following:
-Manually create a new sheet in your workbook. I will refer to this as Sheet2. You can rename it if you wish.
-In Sheet2, in the F(x)= cell, enter 1!A. This will set
all the values in that column to be identical to your input column in
Sheet1 column A. If your data looks different than what I assume, you can adjust accordingly.
-Then, perform the differentiate operation on one of your columns in Sheet1.
-For the output, enter (<input>,Sheet2!<new>). Remember to change Sheet2 if you’ve renamed the sheet earlier.
-Then proceed to “Repeat this for all Y”.
This will output only the derivative of that column to the new sheet and not the input. And should fix the two column output you were seeing before.
There is documentation on output results here that may interest you:
https://www.originlab.com/doc/Origin-Help/AnalyDialog-OutputResult
Please let me know if you have any questions about what I wrote or want help understanding output options.
Chao
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ChaoC
USA
165 Posts |
Posted - 05/13/2022 : 12:19:58 PM
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Hi Leonardo,
The Repeat this for All Y columns has been improved in 2022b.
If you output to a new Sheet and repeat the analysis, it will not add the shared X column, only the Y columns.
Please visit https://www.originlab.com/2022b to learn about the new features and how to upgrade.
Thanks,
Chao |
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Plotting spectra in Origin