Add text about how to set default value in the code by passing name

[asalmgren]

of routine to amrex::Initialize(...)

Summary

Additional background

Checklist

The proposed changes:

• fix a bug or incorrect behavior in AMReX
• add new capabilities to AMReX
• changes answers in the test suite to more than roundoff level
• are likely to significantly affect the results of downstream AMReX users
• are described in the proposed changes to the AMReX documentation, if appropriate

[drummerdoc]

If code within AMReX requires a specific setting of values ParmParse'd within library code to function "correctly" or as expected, (whether that happens to be the default set in the library, or set by an application using this mechanism), it would be helpful to add an AMREX_ALWAYS_ASSERT to the affected library code to ensure that it is set correctly for that usage.

[asalmgren]

Huh? Where would you put the assertion? Currently one application wants to use a different default than is set in amrex and doesn't want to have to add it to every inputs file. What would you assert in this case?

…

On Wed, Aug 12, 2020 at 6:16 PM Marc Day ***@***.***> wrote: If code within AMReX requires a specific setting of values ParmParse'd within library code to function "correctly" or as expected, (whether that happens to be the default set in the library, or set by an application using this mechanism), it would be helpful to add an AMREX_ALWAYS_ASSERT to the affected library code to ensure that it is set correctly for that usage. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1260 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACRE6YUYVFD4KD7GWNBTYCLSAM5GZANCNFSM4P5RNOGQ> .

-- Ann Almgren Senior Scientist; CCSE Group Lead

[drummerdoc]

Let's say that the boundary conditions on the tensor solve are implemented in such a way as to assume that extend_domain_face was true, and let's say that the associated code was buried in the MLMG folder somewhere. Then the assert would go in the tensor solve library code that had that requirement. An application code using the tensor solve could use the mechanism described here to set convenient defaults that are not required by applications not using that tensor solve code.