Integration of Fortran wrapper

[lars2015]

Overview

• A Fortran wrapper for MPTRAC has been developed in the context of the natESM LAGOON sprint.
• The code for the wrapper has been developed separately from the MPTRAC git repo, but should be integrated in the master branch.

Open tasks

• [x] fix remaining issues with wrapper code:
  • [x] fix memory issue when using the wrapper on a notebook (Ubuntu) rather than JUWELS
  • [x] handling of pointer-to-pointer in get_met() function
  • [x] use of argc/argv command line arguments in the wrapper
• [x] adapt Makefile for compiling the wrapper:
  • [x] add a flag WRAPPER to switch on/off the compilation of the Fortran wrapper (if needed)
  • [x] allow for selection of the Fortran compiler (gfortran, nvfortran)
• [x] improve test case:
  • [x] check that Fortran wrapper code uses the same dimensions as the C code (EX, EX, EP, NP)
  • [x] print selected variables from ctl_t, atm_t, met_t in trac_fortran to a logfile, compare logfile with reference output to make sure C-to-Fortran mapping of variables/arrays is correct
• [x] documentation:
  • [x] add markdown page to user/developer manual describing the wrapper
  • [ ] add doxygen documentation to Fortran wrapper and any additional/modified C code

[sabinegri]

The wrapper now runs on the notebook and JUWELS (without MPI!!!). It was tested with GCC+ParaStationMPI, Intel+ParaStationMPI, NVHPC+OpenMPI ().

To achieve this, the following issues were fixed:

• Makefile: added option for Intel compiler for c
• Makefile: added option for Intel and NVHPC compiler for fortran
• mptrac_read_ctl: type of argc and argv. Variables passed to c code must be of a type c understands.
• mptrac_read_ctl: added missing variable in ctl_t
• mptrac_read_ctl: added script to check consistency between structs in c and fortran
• mptrac_read_ctl: fixed data types in subroutine
• mptrac_read_clim: added additional dimensions and structs required by clim_t. As clim_t shall be accessible from fortran, all sub-datatypes (struct clim_photo_t, etc.) must be known in fortran.
• mptrac_read_clim: added data types to subroutine

For debugging the following additions were made:

• print *,c_sizeof calls were added
• add modules.sh to load stage and libraries on JUWELS
• valgrind call in runscript

Please note:

• on the notebook you have to set ulimit -s unlimited. The structs are quite large.
• The NVHPC compiler is not happy with the size of the met_t struct (maybe 2 GB limit?). They are currently setfor ERA5 data. If you make them smaller, let's say so that ERA-interim fits, it works.

ToDo:

• there are several ToDo comments in the code now please work through them and
• clean up (remove unneccessary comments and prints)
• please also check and fix to compile with MPI and GPU later on