Hi Hongcheng, I am sorry I made a mistake in my previous post. Yes, you are right. The samples should be on the zeros of the specific Bessel function, ie, it is not a uniform sampling.
Let's go back to your question. It seems to me that regenerating required non-uniform samples from existing uniform samples would be difficult or impossible unless you have the analytical expression of the transformed function. Best wishes, HZ On Mon, Sep 20, 2010 at 5:33 PM, Hongcheng Ni <[email protected]> wrote: > Hi Hongzheng, > > Thank you for your reply! > > However, look at the third formula in that section (32.1) of the manual, > gsl_dht does require the values of function f at zeros of Bessel > function J_nu. > > - > Best regards, > Hongcheng Ni > JILA, University of Colorado at Boulder > 440 UCB, Boulder, Colorado 80309-0440 > > > On Mon, 2010-09-20 at 17:04 -0400, Hongzheng Wang wrote: >> Hi Hongcheng, >> >> I am afraid you misunderstood the manual of GSL at this point. Just >> take a look at the following quoted sentence in the manual and make >> sure you know what it means: >> >> ``compare this to the case of the discrete Fourier transform, where >> samples are taken at points related to the zeroes of the sine or >> cosine function.'' >> >> In fact, to do a discrete Hankel transform of a particular function f, >> you just need to provide a sequence of samples of f, which normally >> are obtained indeed on a uniform manner. >> >> HZ >> >> On Mon, Sep 20, 2010 at 3:57 PM, Hongcheng Ni <[email protected]> >> wrote: >> > Hi everyone, >> > >> > I'm a newcomer and have a question about discrete Hankel transform (DHT) >> > in GSL package. >> > >> > By reading the manual, I find that gsl_dht only supports a non-uniform >> > grid system in which sampling is done on the zeros of the Bessel >> > function (of the first kind) J_0. >> > >> > Does anyone know how to use it on a uniform grid? (Because changing my >> > existing code from uniform sampling to non-uniform sampling would cost a >> > lot of time.) Thanks! >> > >> > - >> > Best regards, >> > Hongcheng Ni >> > JILA, University of Colorado at Boulder >> > 440 UCB, Boulder, Colorado 80309-0440 >> > >> > >> > >> > _______________________________________________ >> > Help-gsl mailing list >> > [email protected] >> > http://lists.gnu.org/mailman/listinfo/help-gsl >> > > > _______________________________________________ Help-gsl mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-gsl
