Tests

A collection of operating tests for continuous integration and demonstration purposes is provided in the repository. This section describes what they are trying to achieve and how to use them.

Write and Couple

A surrogate geoscientific code with an hard-coded OASIS interface is emulated by toy_earth.py. The script advances in time in accordance with parameters provided in the Fortran namelist earth_namelist. models.py contains a dummy model add_100() that we wish to deploy within Toy Earth.

Toy Earth intends to send:

  • one 2D time-evolving field sst, with a hourly frequency, on grid (720,603)

  • one 3D time-evolving field svt, with a daily frequency, on grid (720,603,3)

  • one fixed metric field msk, only once, on same sst grid

and to receive from the Python model:

  • one field sst_var, computed from sst, with same dimensions

  • one field svt_var, computed from svt, with same dimensions

Eophis script main.py aims to write coupling namelist, configure OASIS interface for models.py, and orchestrate connexions between exchanged data and add_100().

_images/write_and_couple_pipeline.png

In addition to add_100(), Toy Earth adds 0.2 to sst and 0.5 to svt every time step. Given the number of time steps and exchanges, final values are theoretically known. Test is successful if final sst and svt correspond to theory, meaning that coupling and exchanges have been performed correctly, with right frequencies.

It illustrates :

  • Preproduction and Production modes

  • Tunnel configuration and registration for regular and static exchanges of 2D/3D fields

  • Fortran namelist manipulation

  • Writing of coupling namelist

  • Tunnels opening

  • Assembly of a Loop and a Router

  • Model required global structure

  • Static exchange and start of time emulation for regular exchanges

Following commands run the test (number of executing processes may be changed in Makefile):

  • make : execute commands below

  • make clean : remove working files

  • make preprod : execute eophis in preproduction mode to write coupling namelist

  • make prod : execute eophis in production mode for coupling with dummy earth system script

cd tests/write_and_couple
make
python3 ./main.py --exec preprod
mv eophis.out preprod_eophis.out
mpirun -np 1  python3 ./toy_earth.py : -np 1  python3 ./main.py --exec prod
TEST SUCCESSFUL
END OF WRITE AND COUPLE TEST

Halo Decomposition

A surrogate geoscientific code with an hard-coded OASIS interface is emulated by toy_earth.py. The script advances in time in accordance with parameters provided in the Fortran namelist earth_namelist. models.py contains a dummy model deltaxy() that computes first order discrete differences along first and second axis.

Differences imply to know neighboring cells. Those will be missing at boundaries, especially if models.py is scattered among processes. Fields need to be received on the model side with at least 1 extra halo cell to compute correct differences. It is also required to determine the values of the halos located over the edges of the global grid.

Thus, Toy Earth intends to send every time step:

  • psi, on Arakawa C-grid V points, with size (10,10,3), cyclic/NFold conditions and 1 halo

  • phi, on a standard grid, with size (10,10,2), closed/cyclic conditions and 2 halos

and to receive from the Python model:

  • dxpsi and dypsi, results from deltaxy(psi), defined on same psi grid

  • dxphi and dyphi, results from deltaxy(phi), defined on same phi grid

_images/halo_decomposition_pipeline.png

In reality, Toy Earth is supposed to send/receive real cells only, without halos. Eophis goal here is to achieve exchanges with correct automatic reconstruction and rejection of halos. Differences are also computed in Toy Earth and compared with returned results. Test fails if results do not match.

It illustrates :

  • Definition of user-defined grids with halos

  • Definition of grids with different boundary conditions

  • Definition of exchanges with different grids within the same Tunnel

Following commands run the test (number of running CPUs may be changed in Makefile):

  • make : execute commands below

  • make clean : remove working files

  • make preprod : execute eophis in preproduction mode to write coupling namelist

  • make prod : execute eophis in production mode for coupling with dummy earth system script

cd tests/halo_decomposition
make
python3 ./main.py --exec preprod
mv eophis.out preprod_eophis.out
mpirun -np 1  python3 ./toy_earth.py : -np 1  python3 ./main.py --exec prod
TEST SUCCESSFUL
END OF HALO DECOMPOSITION TEST