Re: [Help-gsl] integration w/ qagp, bessel_Jnu

2005-11-17 Thread Jorge Talamantes
>Split up the integral (or integrand) to compute the part near x=0 >using the asymptotic form of j(x,n) for small x to avoid underflow. >Or disable the underflow error if it doesn't affect the final results. > >-- >Brian Gough Hi. Thanks for your reply. I implemented a solution equivalent to yo

Re: [Help-gsl] integration w/ qagp, bessel_Jnu

2005-11-15 Thread Brian Gough
Jorge Talamantes writes: > Dear all, > > I am trying to integrate the following function: > > I = \int_0^{x1} M (D, alpha, x, n) dx, > > where D, alpha and n are parameters to be passed to M, and > > M = x^(D-alpha-1) * [ j(x,n+0.5) ]^2. > > Here, j is the Bessel function of or

[Help-gsl] integration w/ qagp, bessel_Jnu

2005-11-10 Thread Jorge Talamantes
Dear all, I am trying to integrate the following function: I = \int_0^{x1} M (D, alpha, x, n) dx, where D, alpha and n are parameters to be passed to M, and M = x^(D-alpha-1) * [ j(x,n+0.5) ]^2. Here, j is the Bessel function of order (n + 0.5). For some combinations of D and alpha, the