Bessel K Evaluation in LabView

[rlove]

LabView V6.0 only computes real number Bessel J and Bessel Y functions. Does anyone have an algorithm or a vi that will compute a Bessel K function ? I can transform a Bessel K to a function involving Bessel Y and Bessel J, but in the process, I gain imaginary numbers, for which LabView refuses to compute. Any help will be greatly appreciated !

Rafael

[JRA]

Have you tried using the complex number functions in LabVIEW? They might get you going in the right direction.

[RTJ]

I was also suprised to find out that the bessel function in labview was not capable of dealing with complex numbers. Here are two references, I haven't tried either yet.


Amos, D. E., "A Subroutine Package for Bessel Functions of a Complex Argument and Nonnegative Order," Sandia National Laboratory Report, SAND85-1018, May, 1985.

Amos, D. E., "A Portable Package for Bessel Functions of a Complex Argument and Nonnegative Order," Trans. Math. Software, 1986.

Maybe the next release of Labview will include this functionality.

[bul]

I had the same problem also and I wrote the attached simple vi for my calculation. This vi calculates only the Bessel first kind but with some minor modifications can be applied to second kind as well. Note that one should use extended double precision for this calculations.

Hope it would help for you.

Buelent Uensal

[RTJ]

Thanks, I'm interested in routine you posted. I had ended up using the matlab script node and using the matlab bessel routines.