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Inconsistent frequencies solved under various "diff_scheme"

Posted: Thu May 06, 2021 8:10 am
by yaguangli
Hello GYRE users,

I am trying to solve the adiabatic frequencies for a solar model, but I found the frequencies returned from the various schemes (colloc_gl2/colloc_gl4/colloc_gl6/magnus_gl2/magnus_gl4/magnus_gl6) are very different from each other.

This plot shows a comparison between them (the three panels plot the same data but with diff y-axis ranges)
The attachment schemes.png is no longer available
"colloc_gl2" have the most worrisome results. It has a ~5muHz difference at numax and it confuses me with the surface effect at first.
"magnus_gl2" is better but still diff ~0.1muHz at numax, which exceeds the typical observational uncertainty (~0.01muHz).

Is this behaviour intended/unexpected? What do you think the most recommended choice for diff_scheme?
I have attached my gyre inlist and the stellar structural file if you are interested in reproducing my results.
Thanks for any help in advance!

Cheers,
Yaguang

Re: Inconsistent frequencies solved under various "diff_scheme"

Posted: Thu May 06, 2021 8:32 am
by warrick
Hi Yaguang,

Can attach or link to the model you're using, as well as provide your GYRE input (and GYRE version if not the latest 6.0.1)?

Cheers,
Warrick

Re: Inconsistent frequencies solved under various "diff_scheme"

Posted: Thu May 06, 2021 8:47 am
by yaguangli
Hi Warrick,

Sorry, I think my attachments were mysteriously gone.
Here's a link: https://1drv.ms/u/s!AloivC8jPpg0nKIinCL ... g?e=i27eHg
And yes, I am using 6.0.1.

Thanks!
Yaguang

Re: Inconsistent frequencies solved under various "diff_scheme"

Posted: Thu May 06, 2021 8:58 am
by warrick
Here's what I get for ℓ=0,1 and 2 in Model S using the input file in the GYRE tests (i.e. $GYRE_DIR/test/ad/fgong/solar/gyre.in) by cycling through the MAGNUS and COLLOC methods of order 2, 4 and 6. The frequencies are all in μHz. It's qualitatively similar to your plots but the worst errors (for 2nd order methods) are an order of magnitude better.
The attachment gyre_methods0.png is no longer available
gyre_methods0.png
gyre_methods0.png (36.62 KiB) Viewed 2891 times

Re: Inconsistent frequencies solved under various "diff_scheme"

Posted: Fri May 07, 2021 2:58 am
by warrick
yaguangli wrote:
Thu May 06, 2021 8:47 am
Here's a link: https://1drv.ms/u/s!AloivC8jPpg0nKIinCL ... g?e=i27eHg
That folder appears to be empty. Has the link expired?

Re: Inconsistent frequencies solved under various "diff_scheme"

Posted: Fri May 07, 2021 3:34 am
by yaguangli
That folder appears to be empty. Has the link expired?
Sorry, the new link is here:
https://1drv.ms/u/s!AloivC8jPpg0nK1yIHE ... A?e=SgGxUq