Re: Is it "n" or "pi" ?

[Rob Mahurin]

On May 23, 2009, at 3:46 AM, Adrian Spiridon wrote:
>         I want to calculate Bessel function of the second kind , Yn 
> (z)  for n integer, using the formula :http://mathworld.wolfram.com/ 
> images/equations/BesselFunctionoftheSecondKind/ 
> NumberedEquation6.gif  fromhttp://mathworld.wolfram.com/ 
> BesselFunctionoftheSecondKind.html .
>         I am not sure, in the formula, whether it is power(z/2,-n)  
> or power(z/2,-pi), Jn(z) or Jpi(z). Similar,on the last term : is  
> it power(z/2,n) or power(z/2,pi) ?
>         If I zoom the image, it seems to be pi, although n is  
> probably correct.

All of those are "n".  There are solutions to the Bessel equations in  
lots of differential equations books, if you want something with  
enough detail to follow.

> PS:  I know Octave has this function built in, but I want to  
> implement it myself.
>        Also, where can I find the Octave source code of the  
> function bessely ?


http://hg.savannah.gnu.org/hgweb/octave/file/7c02ec148a3c/src/DLD- 
FUNCTIONS/besselj.cc

Cheers,
Rob

--
Rob Mahurin
Department of Physics and Astronomy
University of Tennessee                 865 207 2594
Knoxville, TN 37996                     address@hidden