[Mesa-users] (no subject)

Mon Jun 29 04:48:14 EDT 2020

Dear Dr. Marchant

Thank you so much for the helpful explanation to my question.
I understood the problem in my code.

I wish you the best of luck in your future endeavors.

Best Regards

Ebrahim Hassani

On Mon, Jun 29, 2020 at 12:33 PM Pablo Marchant <pamarca at gmail.com> wrote:

> Hi Ebrahim,
>
> as I mentioned before, MESA allocates arrays larger than what is actually
> needed for the grid size in order to prevent having to do repeated array
> allocations, you're just by random running into the point where the number
> of cells in your stars matches the size of the array.
>
> Let me be more explicit. Imagine your starting model would need 1000
> cells, MESA will create an array with a larger size to store it say 1200
> cells, but anything beyond cell 1000 has no physical meaning, and you cant
> even assure that they will have meaningful values such as zero, so you
> should never access those. Now as your model evolves it might require more
> cells, so it will start filling out those extra 200 empty indices of the
> array. So say in each following step it increases to 1040, 1080, 1100,
> 1170. If at the following step the adaptive mesh algorithm determines 1220
> cells are needed, then it will reallocate all arrays with 1420 cells. In
> this case you would not find the issue you see. Now, just by chance, it
> could happen that in that last step the adaptative mesh says 1200 cells are
> required. In this case no reallocation will be made, and your array will
> have the exact size given by s% nz. It is in this latter case that you run
> into your issue.
>
> Cheers
>
> On Mon, Jun 29, 2020 at 9:05 AM Ebrahim Hassani <ee.haji at gmail.com> wrote:
>
>> Dear Dr. Marchant
>>
>> Thank you for the time you spent answering my questions.
>>
>> May I ask why star evolve until step 1650 (and when its age is about 10
>> Giga Year) and after that, the error occurs?
>>
>> Is my question correct when I say: If my code is wrong the error must
>> occur at the first step and before star starts to evolve.
>>
>> Cheers
>>
>> On Sun, Jun 28, 2020 at 11:03 PM Pablo Marchant <pamarca at gmail.com>
>> wrote:
>>
>>> Hi Ebrahim, please keep mesa-users in your replies.
>>>
>>> as I mentioned you're accessing values beyond s% nz. Just from a quick
>>> glance at your code I see this
>>>
>>>       do i = s% nz, 1, -1
>>>       part3_he4 = part3_he4 + ((avogad * (s% rho(i)) &
>>>       *(s% xa(s% net_iso(ihe4),i)) &
>>>       / (At_he4))) * ((s% r(i))**2) * ((s% r(i)) - (s% r(i+1))) &
>>>       * 1D0
>>>       end do
>>>
>>> when i=s% nz you are reading s% r(s% nz+1) which is wrong. I assume
>>> you're trying to compute an integral in radius here, for that you'll have
>>> to treat the innermost cell in a special way.
>>>
>>> Cheers
>>>
>>> On Sun, Jun 28, 2020 at 7:51 PM Ebrahim Hassani <ee.haji at gmail.com>
>>> wrote:
>>>
>>>> Dear Dr. Pablo
>>>>
>>>> Thank you so much for your useful guidance.
>>>>
>>>> The attached files are the "inlist_project" and the "run_star_extras.f"
>>>> files that I edited and used in my work.
>>>>
>>>> I wonder why the star evolves until step 1650 and after that, the error
>>>> will occur (why the error didn't occur in step 1).
>>>>
>>>> It is worth mentioning that I am using the 12778 version of MESA and
>>>> the 20.3.1 version of MESA SDK in the ubuntu 2020 operating system.
>>>>
>>>> Best regards
>>>>
>>>> Ebrahim
>>>>
>>>>
>>>>
>>>> On Sun, Jun 28, 2020 at 2:26 PM Pablo Marchant <pamarca at gmail.com>
>>>> wrote:
>>>>
>>>>> Hi Ebrahim,
>>>>>
>>>>> can't assess in detail your issue if you do not provide adequate
>>>>> information to reproduce your problem. Please note the section "Post a
>>>>> question to mesa-users" on the webpage to see what information needs to be
>>>>> provided for others to assist you.
>>>>>
>>>>> As the error message indicates, you are trying to access an index of
>>>>> the array beyond its size. You should verify that you do not access
>>>>> anything beyond s% r(s% nz), which specifies the number of grid points in
>>>>> the mesh. Note that the array might have elements beyond s% nz, this is
>>>>> solely because the arrays are allocated with extra space such that each
>>>>> remeshing action that increases the number of grid points does not need
>>>>> another allocation. But anything beyond s% nz should not be used. Beware
>>>>> that you running into this error might be an indication that you are not
>>>>> accessing the physical point you want in your star, but again, absent
>>>>> proper information we cannot assess if this is the case.
>>>>>
>>>>> Cheers
>>>>>
>>>>> On Sun, Jun 28, 2020 at 10:36 AM Ebrahim Hassani via Mesa-users <
>>>>> mesa-users at lists.mesastar.org> wrote:
>>>>>
>>>>>> Dear Mesa-users
>>>>>>
>>>>>> I edited "run_star_extras.f" file and used "s%r" parameter in my
>>>>>> work. Everything is right and my code (for one solar mass star) works
>>>>>> correctly. But after about 1650 steps I encountered with the below error:
>>>>>>
>>>>>> At line 327 of file ../src/run_star_extras.f
>>>>>> Fortran runtime error: Index '1524' of dimension 1 of array 's%r'
>>>>>> above upper bound of 1523
>>>>>>
>>>>>> If I want to evolve the star more than 1650 steps what I must to?
>>>>>> Does the error has physical interpretation?
>>>>>>
>>>>>> Best Regards
>>>>>>
>>>>>> Ebrahim Hassani
>>>>>> _______________________________________________
>>>>>> mesa-users at lists.mesastar.org
>>>>>> https://lists.mesastar.org/mailman/listinfo/mesa-users
>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>> Pablo Marchant Campos
>>>>> M.Sc on Astrophysics, Universidad Católica de Chile
>>>>> PhD on Astrophysics, Argelander-Institut für Astronomie, Universität
>>>>> Bonn
>>>>>
>>>>
>>>
>>> --
>>> Pablo Marchant Campos
>>> M.Sc on Astrophysics, Universidad Católica de Chile
>>> PhD on Astrophysics, Argelander-Institut für Astronomie, Universität Bonn
>>>
>>
>
> --
> Pablo Marchant Campos
> M.Sc on Astrophysics, Universidad Católica de Chile
> PhD on Astrophysics, Argelander-Institut für Astronomie, Universität Bonn
>
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