public static double Y ( int n , double x ) { double by , bym , byp , tox ; if ( n == 0 ) return Y0 ( x ) ; if ( n == 1 ) return Y ( x ) ; tox = 2.0 / x ; by = Y ( x ) ; bym = Y0 ( x ) ; for ( int j = 1 ; j < n ; j ++ ) { byp = j * tox * by - bym ; bym = by ; by = byp ; } return by ; }
Bessel function of the second kind of order n .