| T O P I C R E V I E W |
| noether08 |
Posted - 07/07/2008 : 7:28:55 PM
Hi,
here´s my problem:
I´ve got four point and want to fit this function:
y=P1*(1-exp(-0.213*P2*x)*J0(i*0.213*P2*x))
with P1 and P2 being the parameters ad J0 being the zeroth bessel function.
But when i try to fit this function, Origin always says:
"Unable to compile user defined function"
Does anybody know, what i´m doing wrong? |
| 3 L A T E S T R E P L I E S (Newest First) |
| noether08 |
Posted - 07/08/2008 : 12:45:10 PM
The formula in my first post was the one that was given.
I think, JO should be the zeroth bessel function of the first kind, like on wikipedia, with (i*0.213*P2*x) being the variable of the Bessel function.
I think the problem is that the variable is complex; when i tried J0(0.213*P2*x), i got a fit function from origin. |
| Fay_Guo |
Posted - 07/08/2008 : 01:49:54 AM
Could you give us your exact formula?
Does your "bessel function" is the same as http://en.wikipedia.org/wiki/Bessel_function
Thanks
Fay
Originlab Technical Services |
| larry_lan |
Posted - 07/08/2008 : 12:33:39 AM
Not sure about how you define J0, maybe you should add a * between J0*(
Thanks
Larry
OriginLab Technical Services |
