Dear Sir, thank you for the suggestion. Yes, I tried "gsl_integration_qagiu" , it also couldn't handle the oscillation and finally giving a very large +ve or -ve value.
I am doing multiple integrations(using say gsl_integration_qag) between the zero's of J0(x) and summing up the series using some force convergence method. Its is very slow method. My integral is : I(k)= \int_0^\infty [dx x J0(kx) F(x) ]. comes from I(k)= 1/(2pi)*\int_0^\infty [ d^2x exp(i k.x) F(x)] which is has a form very similar to a Fourier-Transform integration. is there any other efficient method to handle such integral? regards, Prithwish > At Wed, 2 Jun 2010 06:33:16 -0400, > [email protected] wrote: >> I am a beginer with gsl and I am trying to do an integration of the >> form: >> >> \int_0^\infty [ x J0(x) F(x) ]. >> >> J0(x) being oscillatory makes the integrtal +ve and -ve within its >> consecutive zero's. Form of F(x) is such that the overall integrand is a >> decaying function of x. >> >> How to handle this type of integration using gsl. >> >> I tried using "gsl_integration_qag", but its not giving the correct >> results. >> > > Did you try gsl_integration_qagiu (infinite upper limit)? > _______________________________________________ Help-gsl mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-gsl
