[FLASH-USERS] MAG_FACE_VAR and MAGI_FACE_VAR

[Nathan Goldbaum]

Hello all,

I'm currently in the middle of porting a problem to use the unsplit staggered mesh MHD solver included with the newest release of FLASH.  However, I'm unsure how to correctly the face[x,y,z] arrays in Simulation_initBlock.F90.  In Flash.h there are two preprocessor macros to index the first dimension of the array, MAG_FACE_VAR and MAGI_FACE_VAR.  Some of the example initBlock routines (e.g. OrszagTang) in the magnetoHD directory only set MAG_FACE_VAR, leaving the MAGI_FACE_VAR entries zero.  Others (e.g. BlastBS) set both the MAG_FACE_VAR and MAGI_FACE_VAR entries.

I'm curious why there are two face variables - and what the difference is.  I'm also curious whether I should set one or both when I set up my problem.

Thanks very much for your help with this!

Best,

Nathan Goldbaum
Graduate Student
Astronomy & Astrophysics, UCSC
goldbaum at ucolick.org
http://www.ucolick.org/~goldbaum