[Mesa-users] do_element_diffusion = .false. != diffusion_class_factor(:) = 0

[Warrick Ball]

Hi Rob,

I realise that the defaults aren't causing any problems as they are, it's 
just that that's what users will see and use as examples to guide their 
own inlist choices.  I would've made exactly the same mistake as Earl for 
that reason.

I hope that's clearer; sorry if I'm not explaining myself.

Cheers,
Warrick


------------
Warrick Ball
Postdoc, School of Physics and Astronomy
University of Birmingham, Edgbaston, Birmingham B15 2TT
wball at bison.ph.bham.ac.uk
+44 (0)121 414 4552

On Thu, 14 Dec 2017, r.j.farmer at uva.nl wrote:

> Setting arrays like that works in the default files because they get
> compiled into the code not read as a name list.
>
> Rob
>
>
> On 14 Dec 2017 21:28, "Warrick Ball via Mesa-users" <
> mesa-users at lists.mesastar.org> wrote:
>
> Hi Earl, Rich, et al.,
>
> That's interesting and unexpected (at least for me).  An unfortunate
> by-product is then that the defaults files use this "feature". e.g.
>
>       xa_function_weight(:) = 0
>
> in &controls (r10108), among many other places.
>
> Is there any way to make it obvious to users that this doesn't actually
> work?  Writing a comment at each one of these statements in the inlists
> doesn't seem the right way to do it.  Maybe there's a way to crash if the
> user tries?
>
> Cheers,
> Warrick
>
> ------------
> Warrick Ball
> Postdoc, School of Physics and Astronomy
> University of Birmingham, Edgbaston, Birmingham B15 2TT
> wball at bison.ph.bham.ac.uk
> +44 (0)121 414 4552
>
> On Thu, 14 Dec 2017, mesa-users at lists.mesastar.org wrote:
>
>>
>>
>>> On Dec 14, 2017, at 12:47 PM, Evan Bauer <ebauer at physics.ucsb.edu> wrote:
>>>
>>> Hi Earl,
>>>
>>> It looks like your inlist command is only setting the first class factor
> to 0. That is
>>>      diffusion_class_factor(:) = 0
>>> somehow only gets diffusion_class_factor(1) and leaves the rest of them
> untouched. Since the default number of diffusion classes is five, I think
> your inlist needs
>>>      diffusion_class_factor(1) = 0
>>>      diffusion_class_factor(2) = 0
>>>      diffusion_class_factor(3) = 0
>>>      diffusion_class_factor(4) = 0
>>>      diffusion_class_factor(5) = 0
>>>
>>> Somebody who understands fortran namelists better than me can probably
> explain exactly why this is happening, but hopefully the above is an
> adequate solution.
>>>
>>
>> Array assignment in namelists doesn't work; never quite figured out
> whether this is standard-mandated, or an issue with the compiler(s) we use.
> That's why, for array-valued controls, we have to default initialize them
> explicitly rather than doing it from the namelists in star/defaults. Have a
> look e.g. at set_default_controls() in ctrls_io.f90.
>>
>> cheers,
>>
>> Rich
>>
>>
>>> Cheers,
>>> Evan
>>>
>>>
>>>> On Dec 14, 2017, at 3:58 AM, Earl Bellinger <bellinger at mps.mpg.de>
> wrote:
>>>>
>>>> Dear mesa-users,
>>>>
>>>> I am wondering if someone can help me to understand why turning off
>>>> element diffusion yields a different result than setting the diffusion
>>>> factor to 0? I would expect, perhaps naively, for them to yield the
>>>> same result.
>>>>
>>>> Some simple inlists are attached for calculating the first Gyr of
>>>> evolution for a solar mass track. There's a small difference in
>>>> several quantities, for example the effective temperature changes from
>>>> 5643.763 to 5643.913. This is somewhat different from running it with
>>>> diffusion class factor of 1, which gives Teff of 5643.915.
>>>>
>>>> Best regards,
>>>> Earl Bellinger
>>>>
>>>> ---
>>>> earlbellinger.github.io
>>>> Earl Bellinger, Ph.D. Candidate
>>>> Stellar Ages & Galactic Evolution Group
>>>> Max Planck Institute for Solar System Research
>>>> <inlist_diff_off><inlist_diff_0><diff_off.data><diff_0.data>
>>>
>>
>>
>