[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
## Re: [Help-gsl] Numerical integration

**From**: |
Inigo Aldazabal Mensa |

**Subject**: |
Re: [Help-gsl] Numerical integration |

**Date**: |
Thu, 3 Sep 2009 13:21:38 +0200 |

**User-agent**: |
KMail/1.9.10 |

El MiÃ©rcoles, 2 de Septiembre de 2009, Jonny Taylor escribiÃ³:
>* Hi all,*
>
>* My code needs to numerically integrate a function between known finite*
>* limits (which is what currently takes most of its run time), and I am*
>* trying to work out of any of the GSL routines can help with this. The*
>* function has a sort of carrier/envelope form:*
>* f(x) = g(x) exp(i a x)*
>* and I am trying to determine:*
>* int(f(x), 0, x2)*
>
You can try w
>* g(x) is a function which has a known, fairly complicated, but well-*
>* behaved, analytical form (and it doesn't appear possible to even begin*
>* to symbolically integrate either f(x) or g(c))*
>
>* At the moment I am just using a simple Simpson's rule to integrate it.*
>* The carrier frequency is not enormous, but is high enough frequency to*
>* require quite a few sample points. I feel that because of this*
>* specific form there ought to be some sort of shortcut or special*
>* technique that could separate out the "carrier wave", so that*
>* effectively all that needs to be sampled is the slowly-varying*
>* envelope. Can anyone suggest a suitable technique that I could use for*
>* this? (ideally one implemented in GSL, but I can code it up from*
>* scratch if required). Someone suggested to me that some sort of trick*
>* involving fourier transforms might help, but I haven't really got*
>* anywhere with that as yet.*
>
>* Thanks in advance for any suggestions*
>* Jonny*
>
>
>
>* _______________________________________________*
>* Help-gsl mailing list*
>* address@hidden*
>* http://lists.gnu.org/mailman/listinfo/help-gsl*