The MPI - Adaptive Mesh Refinement - Versatile Advection Code (development version)
Dump variables to dat files

There are two ways to add variables to the dat files:

Extra variables

This method adds extra variables in the dat file (which is also used for restart) and it is used in many tests: ard/analytic_test_1d, demo/Advect_ParticleSampling_2D, hd/Gresho_Chan_2D, ... To see all the tests which use this method, in the tests folder run:

find . -name 'mod_usr.t' -exec grep -H "var_set_extravar" {} \;

This method consists in:

  1. Assign an index in the variable list w in usr_init subroutine (in mod_usr.t) using var_set_extravar
  2. Implement one of the user methods which are called every timestep: usr_process_grid, usr_modify_output,... and set there the extra variables (and properly assign the pointer to the implemented subroutine in usr_init).

New dat files

With this method an extra dat file is generated with new variables. (see amrvacio/mod_convert.t).

  1. Set convert_type to "dat_generic_mpi":
           convert_type = "dat_generic_mpi"
  2. Add a convert method in usr_init subroutine (use mod_convert):
     call add_convert_method2(dump_vars, 4, "jx jy jz sxr", "_aux_") 
        call add_convert_method(dump_vars, 4, (/" jx", " jy", " jz", "sxr"/), "_aux_")
    The first way is preferred as because Fortran requires the strrings in an array to have the same length and extra spaces might be necessary for this. The last argument _aux_ is the suffix added to base_filename in order to generate the name of the new dat file.
  3. Implement dump_vars function:
     function dump_vars(ixI^L, ixO^L, w, x, nwc) result(wnew)
       use mod_global_parameters
       use mod_thermal_emission
       integer, intent(in)             :: ixI^L,ixO^L, nwc
       double precision, intent(in)    :: w(ixO^S, 1:nw)
       double precision, intent(in)    :: x(ixO^S,1:ndim)
       double precision    :: wnew(ixO^S, 1:nwc)
       double precision :: current(ixI^S,7-2*ndir:3)
       integer :: idirmin,idir
       double precision    :: tmp(ixI^S)
       call get_current(w,ixI^L,ixO^L,idirmin,current)
       wnew(ixO^S,1) =  current(ixO^S,1)
       wnew(ixO^S,2) =  current(ixO^S,2)
       wnew(ixO^S,3) =  current(ixO^S,3)
       call get_SXR(ixI^L,ixO^L,w,x,te_fl_c,tmp,9,12)
       wnew(ixO^S,4) =  tmp(ixO^S)
     end function dump_vars

    Examples of use in the main code

  1. For the mhd model for dumping full variables by setting in the parameter file:
    A new file is created with hardcoded suffix new.
  2. For the two-fluid model for:
    1. dumping full variables by setting in the parameter file:
      A new file is created with hardcoded suffix new.
    2. dumping the collisional terms by setting in the parameter file:
      A new file is created with hardcoded suffix _coll.