| T O P I C R E V I E W |
| coffeezombie |
Posted - 10/12/2011 : 09:29:28 AM
Origin Ver.: 8.0
Operating System: Windows XP
HI!! GUYS!!
I'd like to fit power like data with not built-in power function (y = (a*(1-x^b))^c )
Hence, I made user-defined function of y = [/b](a*(1-x^b))^c[/b]
If function is y = a*(1-x^b), It is simple. The problem is that I cannot find suitable code about variable c.
The detail of y =a*(1-x^b) is as follows.
sort(x_y_curve);
x_y_curve = ln(x_y_curve);
Dataset dx;
x_y_curve.AttachX(dx);
dx=ln(1-dx);
double coeff[2];
fitpoly(x_y_curve,1,coeff);
a=exp(coeff[0]);
b=coeff[1];
What should I do for it?
With best regards,
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| 1 L A T E S T R E P L I E S (Newest First) |
| Sam Fang |
Posted - 10/19/2011 : 05:52:00 AM
From your script, it seems that your function is:
y=a*(1-x)^b
You should confirm that your power function is
y=(a*(1-x^b))^c
or
y=(a*(1-x)^b)^c
For the latter, over-parameterization exists, there is no unique solution and you should apply constraints.
Sam
OriginLab Technical Services |
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