[Dart-dev] DART/branches Revision: 12598

[dart at ucar.edu]

nancy at ucar.edu
2018-05-23 15:27:37 -0600 (Wed, 23 May 2018)
217
added more comments to the perturb routine to try to
make it more clear what loops are working on what parts.
also changed one variable name to try to be less confusing.

should have no effect on the code execution.




Modified: DART/branches/recam/models/cam-fv/model_mod.f90
===================================================================
--- DART/branches/recam/models/cam-fv/model_mod.f90	2018-05-23 19:47:07 UTC (rev 12597)
+++ DART/branches/recam/models/cam-fv/model_mod.f90	2018-05-23 21:27:37 UTC (rev 12598)
@@ -2055,7 +2055,7 @@
 integer :: iloc, jloc, vloc, myqty
 integer :: max_qtys, j
 
-integer(i8) :: i, items
+integer(i8) :: i, state_items
 integer(i8), allocatable :: my_vars(:)
 
 logical,  allocatable :: do_these_qtys(:)
@@ -2063,7 +2063,9 @@
 
 character(len=*), parameter :: routine = 'pert_model_copies:'
 
-! set by namelist to select using the default routine or the code here
+! set by namelist to select using the default routine in filter
+! (adds the same noise to all parts of the state vector)
+! or the code here that lets you specify which fields get perturbed.
 if (custom_routine_to_generate_ensemble) then
    interf_provided = .true.
 else
@@ -2080,6 +2082,8 @@
 do_these_qtys(:) = .false.
 perturb_by(:)    = 0.0_r8
 
+! this loop is over the number of field names/perturb values
+! in the namelist.  it quits when it finds a blank field name.
 do i=1, MAX_PERT
    if (fields_to_perturb(i) == '') exit
  
@@ -2097,16 +2101,22 @@
 ! get the global index numbers of the part of the state that 
 ! we have in this task.  here is an example of how to work with
 ! just the part of the state that is on the current task.
-items = get_my_num_vars(state_ens_handle)
-allocate(my_vars(items))
+state_items = get_my_num_vars(state_ens_handle)
+allocate(my_vars(state_items))
 call get_my_vars(state_ens_handle, my_vars)
 
-do i=1, items
+! this loop is over all the subset of the state items 
+! that are on this MPI task.
+do i=1, state_items
+
+   ! for each global index number in the state vector find
+   ! what quantity it is. (iloc,jloc,vloc are unused here)
    call get_model_variable_indices(my_vars(i), iloc, jloc, vloc, kind_index=myqty)
 
    ! if myqty is in the namelist, perturb it.  otherwise cycle
    if (.not. do_these_qtys(myqty)) cycle
   
+   ! this loop is over the number of ensembles
    do j=1, ens_size
       state_ens_handle%copies(j, i) = random_gaussian(seq, state_ens_handle%copies(j, i), perturb_by(myqty))
    enddo