Hi there,
just a comment on the new convention for interpolation. Round-off error lead to
problems with
if (x < interp->xmin || x > interp->xmax)
{
GSL_ERROR_VAL("interpolation error", GSL_EDOM, GSL_NAN);
}
if indeed x very close to the boundaries but within the interval [xmin, xmax].
It is probably better to put something like
if (x < interp->xmin*(1.0-1.0e-14) || x > interp->xmax*(1.0+1.0e-14))
{
GSL_ERROR_VAL("interpolation error", GSL_EDOM, GSL_NAN);
}
This allows for a tiny range of extrapolation but fixes the round-off error
problem.
In addition, I was wondering if the GSL team could be interested in some pretty
fast and accurate integration schemes based on the Patterson quadrature rules?
These are fully nested and converge very rapidly. I have the required c++ code
and will be happy to provide them. Certainly, this can only be a base for GSL,
since you guys have much higher coding standards...
Cheers,
Jens
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Jens Chluba Tel. ++1 416 978 5946
or ++1 416 262 8224
Senior Research Associate Fax ++1 416 978 3921
CITA, University of Toronto .+'''+. .+'''+.
60 St. George Street mailto:[email protected]
Toronto, Ontario M5S 3H8 '+...+' '+...+'
Canada
http://www.cita.utoronto.ca/~jchluba/
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