Re: [Help-gsl] Cauchy Principal Value integration

[Brian Gough]

At Tue, 3 Jul 2007 06:42:11 -0700 (PDT),
eknecronzontas wrote:
>      Kind of a n00b question: Do Cauchy principal value integrators
> require that the pole in the integrand be a simple pole? In other
> words, will gsl_integration_qawc work even if my integrand looks
> like f(p)/g(p), where I know that g(p_0)=0 for some p_0, but my
> integrand is not necessarily of the form f(p)/(p-p_0) ? And what
> about for the CERNLIB routine RCauchy?

Hello,

QAWC requires a simple pole, it assumes that the numerator is a smooth
function.  

The chebyshev weighting coefficients are computed for the 1/(x-c)
singularity, but in principle it would be possible to make a modified
routine to compute them for other types of singularity.

-- 
Brian Gough

Network Theory Ltd,
Publishing the GSL Manual - http://www.network-theory.co.uk/gsl/manual/