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Torquil Macdonald Sørensen
Tue, 16 Nov 2010 17:59:01 +0100
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:18.104.22.168) Gecko/20101030 Icedove/3.0.10
I'm having some trouble with gsl_sf_bessel_il_scaled(l,x) for large l / small x.
The problem manifests itself with the error message:
gsl: gamma.c:1454: ERROR: underflow
Default GSL error handler invoked.
This results e.g. from trying to compute gsl_sf_bessel_il_scaled(100, 0.01)
Thus my question:
Can I find documentation that describes for which values of (l,x) for which the
function will compute a value successfully?
On wikipedia I found an asymptotic expression that works fine as long as
0 < x << sqrt(l+1), so I can use that instead if GSL only fails in cases when
that approximation is OK to my accuracy.
But it would be nice if I don't have to experiment to determine for which (l,x)
I can run the GSL function.
Or does anyone know of a more "robust" bessel function, e.g. in a different C /
- [Help-gsl] gsl_sf_bessel_il_scaled,
Torquil Macdonald Sørensen <=