Re: quadl can't integrate sin or cos over a period

[Dmitri A. Sergatskov]

On Mon, Jul 7, 2008 at 11:41 PM, Adam Higuera <address@hidden> wrote:
> When I enter the command:
>
> quadl(@sin, 0, 2*pi)
>
> octave 3.0.1 under Fedora 9 hangs and fails to produce a result.  However,
>

Perhaps it is a bug in the algorithm itself. In any case it does not
really hangs,
it just take a very long time to finish. You can speed it up by specifying
tolerance :

octave:12> tic; x=quadl(@sin, 0, 2*pi, 1e-2); toc
Elapsed time is 0.6039 seconds.
octave:13> x
x =  1.3878e-16
octave:14> tic; x=quadl(@sin, 0, 2*pi, 1e-3); toc
Elapsed time is 2.542 seconds.
octave:15> x
x =  1.1102e-16
octave:16> tic; x=quadl(@sin, 0, 2*pi, 1e-4); toc
Elapsed time is 7.278 seconds.
octave:17> x
x =  1.1102e-16
octave:18> tic; x=quadl(@sin, 0, 2*pi, 1e-5); toc
Elapsed time is 28.99 seconds.
octave:19> x
x =  1.1102e-16
octave:20>

Dmitri.
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