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glorianic
Italy
3 Posts |
 Posted - 05/10/2023 : 05:17:59 AM
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Origin Ver. and Service Release (Select Help-->About Origin):OriginPro 2023 (64-bit) 10.0.0.154
Operating System:Windows 10 Pro
Hello everyone
I need to calculate the area of some peaks in my plot. To have a precise baseline I was told to reproduce the same plot but upside down, intersecate all the bases of the peaks and take as the baseline the line connecting the intersecation points.
My problem here is that I can only move the graph up and down, but I can't rotate it. Is there a solution to this problem?
If no, how can I have a reproducible baseline?
Thank you so much
Gloria |
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YimingChen
1685 Posts |
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glorianic
Italy
3 Posts |
Posted - 05/10/2023 : 11:27:09 AM
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Thank you for your answer 
I know about the Integration function, and I will use it as soon as I have the baseline that I want.
My problem here is the production of the baseline.
Gloria |
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snowli
USA
1446 Posts |
Posted - 05/10/2023 : 3:53:41 PM
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What do you mean by reverse the plot?
Suppose your plot is from column B of a worksheet, u can add column C with some F(x) formula such as 100-B, etc. to get a reversed data?
U can plot both B and C in same graph and use Gadget: Intersect to get intersecting points.
Then use it as needed.
If you want to interpolate/extrapolate such intersecting points, u can use Interpolate/extrapolate tool
or plot B and use Analysis: Peak and Baseline: Peak Analysis and choose Create Baseline goal on 1st page. Specify existing data as baseline and pick the created column for intersection points to create baseline.
Thanks, Snow |
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glorianic
Italy
3 Posts |
Posted - 05/11/2023 : 02:59:31 AM
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Thank you!
That is what I did in the first place, plot -B, modify the offset of the reversed plot in order to have the intersection points, obtain the baseline that passed from those points and use it as baseline in the Peak Analyzer.
But, as you can see in the image, there are two peaks left out, and I want also those peaks to intersecate, in order to obtain a more precise baseline.
So my question here is, can I rotate the red plot in order to make every peak base intersecate?
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YimingChen
1685 Posts |
Posted - 05/11/2023 : 10:10:46 AM
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But here the question is the offset of the flipped spectrum directly influences the intersected points and subsequently the baseline. Is there a reference you can provide that explains this baseline detection technique?
Please refer to the page below on the two methods to determine a baseline. One is the 2nd Derivative method, and the other is the ALS (Asymmetric Least Squares) method. Hope it is helpful.
https://www.originlab.com/doc/Tutorials/Create-Subtract-Baseline
James |
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Intersecate two graphs to create a baseline