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Janaka
Sri Lanka
15 Posts |
 Posted - 07/01/2014 : 04:40:56 AM
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Origin Ver. and Service Release: OriginPro8 and v8.0988
Operating System: Windows 7
Hi All,
May I know how to extrapolate a curve to a "required" y value (e.g., 140 on the curve shown below)?
Thank you,
Janaka
Janaka |
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SeanMao
China
288 Posts |
Posted - 07/01/2014 : 06:21:50 AM
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Hi Janaka,
You can set your original X column as Y and use Y column as X, therefore you can input 140 as "X Maximum" in "Analysis:Mathematics:Interpolate/Extrapolate:Open dialog". Similarly, you can use "Interpolate/Extrapolate Y from X" to extrapolate at given X values (which is your Y).
Best regards!
Sean
OriginLab Tech. Service
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Janaka
Sri Lanka
15 Posts |
Posted - 07/01/2014 : 11:49:12 PM
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Hi Sean,
Thank you for the details but the first option doesn't make a correct extrapolation as you can see below. I am still trying the 2nd option.
Note: Here "linear" extrapolation was used as "method" and the other two gave even more unaccepted curves.
Janaka |
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Janaka
Sri Lanka
15 Posts |
Posted - 07/02/2014 : 01:10:19 AM
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Hi Sean,
Could you please explain how to select "data range for input" (see on the attachment) for your 2nd option? Though I selected two columns, it still asks to select data for input range.
Janaka |
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SeanMao
China
288 Posts |
Posted - 07/02/2014 : 01:59:17 AM
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Hi Janaka,
For "Interpolate/Extrapolate Y from X", you have to prepare an additional X column other than original XY columns to calculated interpolated/extrapolated Y at all X values from that provided X column.
For extrapolation, the uncertainty in Y is very big when the extrapolated X is far from input X range as you have shown in your graph with "line" method.
The best way to solve your problem is to use Non-Linear Fit (NLFit) tool to fit your data with either build-in function or user defined function which predicts more reasonably according to fitting function.
You can go to "Analysis:Fitting:Non-Linear Curve Fit:Open dialog" to bring up dialog, and in the "Setting" tab "Find X/Y" page, you have the options to "Find X from Y" or "Find Y from X".
You can refer to the video tutorial below to perform it:
http://www.originlab.com/Index.aspx?go=Support/VideoTutorials&pid=1767
Regards!
Sean
OriginLab Tech. Service
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Janaka
Sri Lanka
15 Posts |
Posted - 07/02/2014 : 02:41:25 AM
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Hi Sean,
Thank you for information. Do you have a video for "Interpolate/Extrapolate Y from X" too? I am yet to find how to do it?
Thank you,
Janaka
Janaka |
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SeanMao
China
288 Posts |
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Topic |
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How to extrapolate to "required" y?