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soum
France
5 Posts |
 Posted - 12/13/2017 : 1:45:46 PM
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Origin Ver. and Service Release (Select Help-->About Origin):
Operating System:
Hello,
I have two problems :
1) I have fitted my data with a sine curve and want to extend it to x axis. I don't find any option that allows me that, I have already used "Span to full axis range" but it doesn't intercept with X axis. I want to force the fit to cross the X axis.
2) It is impossible to plot data from an excel Sheet. It works with origin workbook but not with excel, I have tried to create a new excel or to open an existing excel workbook but it doesn't work anymore ( and it worked before!).
Thank you for your help!
Sou
Soum |
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arstern
USA
237 Posts |
Posted - 12/13/2017 : 4:11:47 PM
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Hi Soum,
1. To fit the curve so that it extends to the x-axis. In the Nonlinear Fit dialog -> Select Fitted Curves under Settings -> Under X Data Type select the Custom tab for Range. Unselect Max and input the maximum value. For this example input 2*pi ~ 6.28318531.
2. Here is our documentation on importing excel files/data into Origin:
https://www.originlab.com/doc/Origin-Help/Work-With-Excel
Thanks
Aviel
OriginLab
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soum
France
5 Posts |
Posted - 12/13/2017 : 5:14:53 PM
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Hello Aviel,
I don't how it works, but it does exactly what I was looking for! Thank you so much!!!!
Concerning the second problem, I have already checked your page and I have already plotted data with excel sheet, but the problem here is different : when I click on "scatter", nothing happens and when I do the same thing on Origin workbook, it is working. I can't do any operation with origin if it's an excel workbook. The " Select Data for Plotting dialog" doesn't appear anymore.
Soum
Soum |
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soum
France
5 Posts |
Posted - 12/13/2017 : 5:38:09 PM
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In fact It didn't work for another curve. Here is an exemple of the curve that I have :
I have few points but I know that the fitting curve is a sine and I know that it intersects the x axis.
Soum |
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cpyang
USA
1406 Posts |
Posted - 12/13/2017 : 9:36:05 PM
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You need to import from Excel, rather then Open Excel book inside Origin, as most Origin things cannot really be done from Excel book.
As for your data, can you fix y0=0, or set a constraint so y0 is close to zero so you can force the fit to go below the X axis?
CP
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soum
France
5 Posts |
Posted - 12/16/2017 : 5:53:44 PM
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How can I fix Y0=0? I don't know the x value for y=0.
Soum |
Edited by - soum on 12/16/2017 5:54:16 PM |
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arstern
USA
237 Posts |
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soum
France
5 Posts |
Posted - 12/24/2017 : 3:19:27 PM
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Hello,
I have already been on this page and most of the methods are not or for sine curve. I have tried to fix yO like you said and unfortunately it does not work at all as you can see there : 
Have you another idea? or it is just impossible ? Thank you again.
Soum |
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easwar
USA
1964 Posts |
Posted - 12/26/2017 : 5:31:48 PM
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Hi Soum,
In addition to fixing y0 to 0, you may also need to place some bounds on other parameters such as the w parameter, as in this result I got with your data (I digitized your data using Origin's built-in digitizer):
You may then want/need to put bounds on other parameters as well. It would work better if you had more data points that covered a wider range of the x scale...
Easwar
OriginLab |
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Fitting Sine curve
