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Re: some problem with QAWF integration


Hi,

I think this method should work. Maybe I don't know
how to set the sizes of *wp, *c_wp and n parameter in
qawo_table.

If the problem is "roundoff error detected in
extrapolation table" and I traced it happen at
subinterval_to_small(). Which parameters should I
adjust?

Thanks.
Qiong

--- Brian Gough <bjg@network-theory.co.uk> wrote:
> xie qiong writes:
>  > Hello there,
>  > 
>  > I have an urgent question about QAWF function.
>  >  
>  > I need to computer a semi-infinit integration
>  > \int_{0} ^{\infty} f(x)*sin(w*x)/x dx
>  > The integrand f(x) * sin(w*x) / x has a finite
> value
>  > limit(equal to w) at x = 0.0 but f(x) / x doesn't
> a
>  > finite value limit at x = 0.0.
>  > 
>  > In this case, what can I do to make QAWF work?
> 
> Break the integration range into two parts (0,pi/w)
> (pi/w,inf) and
> compute the first with a standard integrator.
> 
> Brian
> 
> 
> 


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