[SciPy-user] Bug in scipy.special.ivp

[Travis Oliphant]

Takanobu Amano wrote:
> Hello,
>
> I found a small bug in scipy.special.ivp (scipy/Lib/special/basic.py)
> this patch is for the latest svn snapshot (revision 1882).
>
> Takanobu Amano
>
> --- basic.py.orig       2006-06-13 14:29:05.766772544 +0900
> +++ basic.py    2006-06-13 14:23:58.534420748 +0900
> @@ -168,7 +168,7 @@
>      if n == 0:
>          return iv(v,z)
>      else:
> -        return (ivp(v-1,z,n-1) - ivp(v+1,z,n-1))/2.0
> +        return (ivp(v-1,z,n-1) + ivp(v+1,z,n-1))/2.0
>
>   
Nice catch.  Thank you.  The other modified Bessel Function also has an 
incorrect  recurrence relation.  Thank you for finding this.

-Travis