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edwardclhuang
Taiwan
9 Posts |
 Posted - 11/20/2011 : 2:31:17 PM
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Origin Ver. and Service Release (Select Help-->About Origin): Origin8, SR4
Operating System:Win7, 64bit
Dear Sirs
I have to questions in this post. I have read some tutorials but still not so sure how I can proceed it. Please help me figure it out and thanks so much in advance.
1. I have a set of data and I would like to fit them with the following equation,
Independent Variables: x
Dependent Variables: y
Parameter Names: A0, A1, A2, A3, A4
It seems I can use "Labtalk" or "OriginC" to compute it, am I right? Please teach me how to do it.
2.After I get the best fitting results of A0~A4, how can I subtract this function with them in "Set Column Values "? I mean I have another set of data and I want to subtract the function as posted with known A0~A4.
Once again, any help or tutorial would be much appreciated.
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Hideo Fujii
USA
1582 Posts |
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edwardclhuang
Taiwan
9 Posts |
Posted - 11/23/2011 : 09:35:32 AM
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Hello Hideo Fuji
Thanks for the help. Based on your suggestion, first of all I rewrite my function as following,
A0,A1,A2 are fitting parameters. If I replace A2/x = x and abbreviate the equation as following,
Then it comes a problem: I can not get A0, A1, and A2 apart from each other!!
Back to the first equation shown above, I am stuck on the upper bound in the integral(A2/x). Because it also shows in the formula for doing calculation. How can I do that by NAG library? I have tried to write this as
struct user
{
double A2c;
};
static double NAG_CALL f_callback(double x, Nag_User *comm)
{
struct user *sp = (struct user *)(comm->p);
double A2c;
A2c = sp->A2c;
return (A2c/x)^4 * exp(A2c/x) / ((exp(A2c/x)-1)^2);
}
How should I write in the "editable part" please? It seems I should replace "d01smc" formula by some other formulas, and what will be the proper formula?
I am really appreciated with your kindly help. |
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Fit data with integration&summation functions