| 16 | | • the number of copies of the whole namelist (2 by configuration and an increasing number of reference configuration) make the change in namelist a nightmare[[BR]] • default values of the namelist appear twice: 1) in the namelist itself and 2) in the code, distributed in the declaration phase of numerous modules[[BR]] • global domain sizes (jpiglo, jpjglo, jpidta, jpjdta, jpkdta) are FORTRAN parameters, except in AGRIF case ==> almost as many par_XXX.h90 as the number of reference configurations ! [[BR]] • in the code old namelist variables (i.e. with a non-doctor name) still survive ==> suppression is needed. |
| | 16 | • the number of copies of the whole namelist (2 by configuration and an increasing number of reference configuration) make the change in namelist a nightmare[[BR]] • default values of the namelist appear twice: 1) in the namelist itself and 2) in the code, distributed in the declaration phase of numerous modules[[BR]] • global domain sizes (jpiglo, jpjglo, jpidta, jpjdta, jpkdta) are FORTRAN parameters, except in AGRIF case ==> almost as many par_XXX.h90 as the number of reference configurations ! [[BR]] • in the code old namelist variables (i.e. with a non-doctor name) still survive ==> suppression is needed. |
| 18 | | == [[BR]]Proposed solution == |
| 19 | | ''' I -''' global domain sizes, configuration names, etc... (all the PARAMETER in par_oce.F90) defined in the namelist. Impact: suppression of all par_XXX.h90 files. Also suppression of all key_XXX associated to configurations (key_ORCA_RXXX, key_EEL_RXXX, key_GYRE, etc...). |
| | 18 | == [[BR]]Proposed SOLUTION1 (december 2012) == |
| | 19 | ''' I -''' global domain sizes, configuration names, etc... (all the PARAMETER in par_oce.F90) defined in the namelist. Impact: suppression of all par_XXX.h90 files. Also suppression of all key_XXX associated to configurations (key_ORCA_RXXX, key_EEL_RXXX, key_GYRE, etc...). |
| 21 | | ''' II -''' namelist:[[BR]] • One single whole by medium (ocean, ice, top, ...: ''' namelist_ref''' , namelist_ice_ref, name list_top_ref, ...) put at CONFIG/ level in read-only mode. This namelist contains the default values. The hard coded default values spread in the modules are suppressed (together with the surviving old non-doctor variables). [[BR]] • In each configuration the namelists of each medium contain only the changes associated with the configuration (the name may be ''' namelist_cfg''' , namelist_cfg_top, etc...). A pearl script will be used to build the all the namelists that are required to run NEMO: [[BR]] |
| | 21 | ''' II -''' namelist:[[BR]] • One single whole by medium (ocean, ice, top, ...: ''' namelist_ref''' , namelist_ice_ref, name list_top_ref, ...) put at CONFIG/ level in read-only mode. This namelist contains the default values. The hard coded default values spread in the modules are suppressed (together with the surviving old non-doctor variables). [[BR]] • In each configuration the namelists of each medium contain only the changes associated with the configuration (the name may be ''' namelist_cfg''' , namelist_cfg_top, etc...). A pearl script will be used to build the all the namelists that are required to run NEMO: [[BR]] |
| 23 | | namelist == namlist_ref + namelist_cfg changes[[BR]]namelist_top == namlist_top_ref + namelist_top_cfg changes[[BR]]etc ... |
| | 23 | namelist == namelist_ref + namelist_cfg changes[[BR]] namelist_top == namelist_top_ref + namelist_top_cfg changes[[BR]] etc ... |
| | 24 | |
| | 25 | == Discussion == |
| | 26 | Initialization of the variables |
| | 27 | |
| | 28 | Up to now, these namelist variables are initialized twice: hard coded default values spread in the modules, and in the namelist file. Suppressing the hard coded initialisation opens possibility for no initialisation at all (if something is mispelled in the namelist for example). In that sense, removing the hard coded initialisation may be questionnable. |
| | 29 | |
| | 30 | SOLUTION1: some critics |
| | 31 | |
| | 32 | The option is to have a unique complete reference namelist, and a smaller "configuration specific" on containing only the values changed from the reference namelist. This implies and additional step before execution: a merge of the 2 namelists (reference overwritten by specific) to build the third namelist, the one to be used at execution time. The perl script to do that is already written (sent by Marcello Vichi) I see to major defaults with this solution: |
| | 33 | * adding a new step in the execution process is an additional burden. We should look at it carefully before making such a choice. On a technical level, is it obvious that perl will be available on each computing platform? At a user level, it is one thing more not to forget, which cannot be automated neither at compilation (not the right place since namelist can be changed a number of time without changing executable) nor at execution (not an appropriate risk to take if crashes in a batch job) time |
| | 34 | * once the new namelist is created (the first time), my guess is that users will change this "execution namelist" if needed, and not the "configuration" one, in order not to have to do ther merge namelist step again. Mainly this choice means that in order to be sure of what is done, user will have to check 3 namelists (rahter than 1): the reference, the configuration, and the execution one. This seems to be too much |
| | 35 | |
| | 36 | |
| | 37 | == Proposed SOLUTION2 == |
| | 38 | Another way to look at the question: |
| | 39 | * a default initialisation is left in the fortran code, in the module where the namelist variables are declared, used, with all the comments... |
| | 40 | * a configuration namelist containing only the values departing from this default, is available in the CONFIG/CONFIG_NAME/EXP00 directory (like now, but a smaller one) |
| | 41 | * no reference unique default namelist anymore, BUT |
| | 42 | * a complete print of all namelist values is created at the first time step in a separate "output_namelist_xxx" file, aside from ocean.output, in order for the user to know exactly what is done in the run, and what are the values for all these namelist variables |
| | 43 | * this suppresses the reference namelist, and above all the additionnal "merge namelist" step |
