Re: roundoff error prevents tolerance

[Peter Johansson]

Hi Patrick,

On 9/8/22 23:07, Patrick Dupre wrote:
> Hello,
>
> Using
> status = gsl_integration_qag with
>   abs_err: 1e-07 rel_err: 1e-07, size: 200, key: 1
>
> I get
> gsl: qag.c:247: ERROR: roundoff error prevents tolerance from being achieved
> Default GSL error handler invoked.
>
> The bizarre thing is that the code fails without returning the status.

You can change the behavior when an error is detected by providing your 
own error_handler via the function gsl_set_error_handler. The default 
GSL error handler is calling abort, which is not always ideal.

https://www.gnu.org/software/gsl/doc/html/err.html#error-handlers

Cheers,

Peter