This is the mail archive of the
gsl-discuss@sourceware.org
mailing list for the GSL project.
Re: odeiv2 request
- From: Tuomo Keskitalo <tuomo dot keskitalo at iki dot fi>
- To: Patrick Alken <patrick dot alken at colorado dot edu>
- Cc: "gsl-discuss at sourceware dot org" <gsl-discuss at sourceware dot org>
- Date: Sun, 4 Mar 2012 09:02:15 +0200
- Subject: Re: odeiv2 request
- Authentication-results: mr.google.com; spf=pass (google.com: domain of tuomo.keskitalo@gmail.com designates 10.204.156.77 as permitted sender) smtp.mail=tuomo.keskitalo@gmail.com; dkim=pass header.i=tuomo.keskitalo@gmail.com
- References: <4F50F1BE.10603@colorado.edu>
Hello,
that's an interesting use case. May I ask why you needed to integrate
backwards? Did you use driver_apply for integration?
I haven't really considered anyone "hotswapping" the direction of
integration using driver functions.. I think that the stepper at least
must be reset if integration direction is changed, to be safe with
multistep methods. This needs some thinking and testing. I can try to
see to this in a week or few.
Tuomo
On Fri, Mar 2, 2012 at 6:13 PM, Patrick Alken
<patrick.alken@colorado.edu> wrote:
> I had a problem recently where I needed to integrate forward along a curve
> (positive step size h) and then integrate backward again (negative h). But
> there is currently no way to change the sign of the step size h using the
> driver routines, so I had to modify driver->h directly.
>
> I propose adding a routine gsl_odeiv2_driver_set_h() to allow the user to
> reset the step size to what they want. Tuomo: do you see any negative issues
> with this? I can make the addition if you want.
>
> Thanks,
> Patrick
--
Tuomo.Keskitalo@iki.fi
http://iki.fi/tuomo.keskitalo