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hch2008
China
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 Posted - 05/25/2008 : 2:47:24 PM
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Origin Version 7.5 Operating System: window xp
There are four sets of data: x, a(x), b(x) and c (x)
but a,b,c has nothing to do with x at all. x is just used as index.
at any point of x, c(x)= a(x)*N + b(x)*K + M
N,K,M are to de determined.
Does anyone know how to fit this model.
Thank you in advance, helps are so much appreciated!
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Shirley_GZ
China
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Posted - 05/26/2008 : 03:28:38 AM
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Hi, Ch Huang
There are two independent variables and one dependent variable in your dataset.
In Origin 7.5, you can fit your model as following steps:
1. Choose Analysis: Non-linear Curve Fit: Advanced Fitting Tool from main menu to open the Edit Function dialog box .
2. Choose Function: New to build a new user-defined function ,then you can edit your function as below:
3. Click on the Edit in Code Builder button to compile this function. Then you can save this function as any name you want when the compile is done.
4. Choose Action: Dataset from main menu of this dialog box to assign your dependent variable(y) and independent variables (xa,xb). The detail can be seen in our Help by clicking F1.
5. Choose Script: Parameter Initialization from main menu of this dialog box to set the initial value of your parameter.
6. Finally, you can finish your fitting by choosing Action:Fit from the menu.
In Origin 8.0, there is a powerful function of Multiple Regression, which can do this task more easily.
Shirley,
Originlab Technical Service Team
Edited by - Shirley_GZ on 05/26/2008 03:30:02 AM |
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Help , about fitting