Re: [mesa-users] negative delta nu!?!

[Jean M. <je...@nm...>]

r9680. Don't remember why I'm using that one though... I think it is using
a newer version of GYRE.

I must have over looked the l0_n_obs(:) line when i copied an inlist form
some other project over. If I change that to be <0 it no longer produces
negative delta_nu! Problem solved, just a user error.

I'll try commenting those lines and see if the error goes away. It is
clearly calculating the modes, plotting them, and moving on in the code
either way. Just a nuisance at this point.

2017-05-10 3:57 GMT-06:00 Warrick Ball <wb...@bi...>:

> Hi,
>
> So I looked into the issue with the "failed to find required l=0 modes"
> message to try to make sense of what's going on.  I think the segment of
> code that causes the error message to be printed is unchanged from my
> original report, and I've again concluded that it isn't a cause for
> concern, except that the message doesn't correspond to what has happened in
> the code.
>
> Actually, looking at the code, I'd say the line that prints the message
> "failed to find required l=0 modes" is almost unnecessary.  It relies on
> the ouptut of get_radial, which, in almost each case, will print its own
> message about why the code didn't proceed to compute the higher-degree
> modes.  The one case that currently doesn't print an error message is if
> the oscillation code itself fails.  Here are lines 637--646, inside
> get_radial:
>
>     call get_one_el_info(s, 0, &
>        nu_lower_factor*l0_obs(1), &
>        nu_upper_factor*l0_obs(nl0), &
>        iscan_factor_l0*nl0, 1, nl0, store_model, &
>        code, ierr)
>     if (ierr /= 0) then
>        !write(*,'(a65,i6)') 'failed in oscillation code', s% model_number
>        !stop
>        return
>     end if
>
> Any such early return means the function will return .false. and MESA
> won't compute the non-radial mode frequencies.  I'm not sure why the error
> message "failed in oscillation code" is commented out: I'd find that quite
> useful!
>
> So, for extras_support.f in r9575, I suggest:
> - commenting line 374 and
> - uncommenting line 643 (maybe with mention that it's in the radial mode
>   calculation).
>
> For other angular degrees, MESA just prints an error message if the
> oscillation code returns with ierr /= 0, so I don't think any changes are
> warranted.
>
> Cheers,
> Warrick
>
>
>
> ------------
> Warrick Ball
> Postdoc, School of Physics and Astronomy
> University of Birmingham, Edgbaston, Birmingham B15 2TT
> wb...@bi...
> +44 (0)121 414 4552
>
> On Wed, 10 May 2017, Warrick Ball wrote:
>
> Hi Jean,
>>
>> On the first issue, I started your run a few minutes ago but it looks
>> like it'll take a while to finish.  Out of curiosity, which revision are
>> you using?  Your GYRE input gave me a read failure in r9575 (no namelist
>> object "diff_scheme") so I've just used the default for now.
>>
>> Regarding the "failed to find required l=0 modes", I looked into this
>> over two years ago:
>>
>> https://sourceforge.net/p/mesa/mailman/message/33028229/
>>
>> Ignore my proposed fix: that wasn't the solution.  It seems Rich started
>> looking into where the code changed but I couldn't find anything further on
>> the mailing lists.  I've cc'ed Rich, in case he can recall if he made any
>> progress.
>>
>> As far as I know, it's nothing to worry about.  But now that you've
>> brought it up again, it's inspired me to have another close look at why the
>> message is issued and what should be happening instead.  Hopefully more as
>> the day progresses here.
>>
>> Cheers,
>> Warrick
>>
>> PS:  I noticed your inlist has the line
>>
>>      l0_n_obs(:) = 6 ! the observed radial orders (ignored if < 0)
>>
>> AFAIK, this should be the observed radial orders of the radial modes,
>> which presumably aren't all 6!  (You can choose to let MESA infer the
>> radial orders of the modes: see lines 660--686 in
>> $MESA_DIR/star/astero/work/astero_support.f.)
>>
>>
>>
>> ------------
>> Warrick Ball
>> Postdoc, School of Physics and Astronomy
>> University of Birmingham, Edgbaston, Birmingham B15 2TT
>> wb...@bi...
>> +44 (0)121 414 4552
>>
>> On Tue, 9 May 2017, Jean McKeever wrote:
>>
>>  Here are the inlists I used.
>>>
>>>  2017-05-08 17:22 GMT-06:00 Jean McKeever <je...@nm...>:
>>>        Hello,
>>>
>>>  I am running some models using astero and have ran into an interesting
>>>  conundrum. As soon as astero starts computing individual frequencies,
>>> the
>>>  delta_nu value, both printed on the graph display and
>>>  written to the history file, becomes negative.  I am using gyre to
>>> compute
>>>  only radial modes. Has anyone else encountered this or something
>>> similar?
>>>
>>>  On another note I am constantly getting  a "failed to find required l=0
>>>  modes" message, however modes appear on the echelle diagram. I have
>>> double
>>>  checked my gyre input files are in the right units and
>>>  cover the range of observed modes. Is this something to worry about?
>>>
>>>
>>>  Jean McKeever
>>>
>>>
>>>
>>>
>>>