evaluating bessel functions

[Jim_81]

I have labwindows 7.1 and wanted to evaluate bessel functions for zeroth order and possibly other higher orders.  Is there a built in function to calculate the bessel function J_n(x) where n is the order?

[duncan carter]

"Numerical Recipes in C" has source code for evaluation of Bessel functions.

See:
http://www.nr.com/

and

http://www.library.cornell.edu/nr/cbookcpdf.html   - Chapter 6

and

http://forums.ni.com/ni/board/message?board.id=180&message.id=17112#M17112

Message Edited by duncan carter on 01-04-2006 09:51 AM

[Graziano]

Hi!

   You can calculate Bessel filter coefficients (for IIR filter) if you have Advanced analisys library, that contains many useful functions for DSP (and more).

   If you really need to evaluate Bessel function, Duncan is rigth, Numerical Recipes in C is the answer!
   Only take care that you have to include Numerical Recipes header files, which are listed in the book appendix (if I'm not wrong...).  I already used NR functions, in a former project, and it was quite great.

   I don't know if DSP toolkit (an add-on for LabWindows, http://sine.ni.com/nips/cds/view/p/lang/it/nid/11123 ) contains functions regarding this.... maybe you should ask NI!  I didn't find at a first look a complete list of functions....

   Hope it helps!

graziano

[Mohan]

If you have CVI 8.0, the Advanced Analysis library has the Bessel functions. The CVI function names are: Bessel1st and Bessel2nd. Older versions of CVI do not have these functions.

[Jim_81]

Thanks I just wrote my own since I couldn't find any algrothims that handled complex numbers.

[Graziano]

Hi!

By the way, Mohan, can you clarify the difference between DSP toolkit, and Advanced analisys library?

Thanks!!!

graziano

[Mohan]

I really have no idea about the DSP toolkit. The Advanced Analysis library is the analysis library shipped with the FDS version of CVI.