| T O P I C R E V I E W |
| judithsu |
Posted - 08/30/2005 : 6:56:13 PM
Origin Version (Select Help-->About Origin): 6.0
Operating System: win xp
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Hi, I'm interested in doing a linear regression (y = a + bx) to a set of data points accounting for the error in x and the error in y. I'm interested in the values of a and b, their uncertainity, and the chi-squared value. Does Origin already have this capability and if so how would I access it. Any help would be greatly appreciated. Thank you very much! |
| 1 L A T E S T R E P L I E S (Newest First) |
| Mike Buess |
Posted - 08/30/2005 : 9:38:08 PM
There are several ways to fit to a straight line in Origin but I think you need the nonlinear curve fitter to get chi-sqr...
Help > Origin > Curve Fitting > The Nonlinear Least Squares Fitter
The line function is in the Polynomial fitting category which was disabled for some reason in Origin 6.0. To enable that category close Origin, find NLSF.ini in your Origin folder and open it in Notepad. In the [Category] section you will find the line
;Polynomial=fitfunc
Remove the semicolon (;) and save your changes. When you start Orign you will see a Polynomial category in the nonlinear curve fitter. Select that category and the Line function within.
...Just noticed that you wanted to take into account errors in X. That's not possible, the fitter will only handle errors in Y.
Mike Buess
Origin WebRing Member
Edited by - Mike Buess on 08/30/2005 10:32:26 PM |
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