A Python interface to the Fortran-written data assimilation library - PDAF

• Fortran compiler: e.g.:gfortran/intel fortran
• a message passing interface (MPI) implementation: e.g. openMPI/MPICH
• Python>=3.8

• pyPDAF uses [PDAF V2.1](https://github.com/PDAF/PDAF/tree/PDAF_V2.1) which can be obtained by: git submodule update --init --recursive
• Currently, Fortran-written PDAF is compiled together with pyPDAF. Hence, the Fortran compiler options need to be specified in the PDAF section of setup.cfg.
• Options in pyPDAF section of setup.cfg are related to the current pyPDAF directory (pwd) and C compiler used by Cython, e.g. (CC=mpicc for GNU compiler or CC=mpiicc for Intel compiler)
• It is recommended to use a clean conda environment to install pyPDAF to avoid any package conflicts
• Install Python package: pip install .

mpiexec -n 4 python -u example/main.py

Will run the model with 4 ensemble members where each member uses 1 process.

Currently, it interfaces with subroutines of PDAF-V2.1 with an example for online coupling with PDAF using a simple model based on the tutorial from PDAF. Some interface in Python changes slightly due to different ways to handling return values in Python from Fortran.

This documentation contains more details on installation, Python interface, and implementation guide on pyPDAF. The simplified interfaces in PDAF are not supported.

Yumeng Chen, Lars Nerger

pyPDAF is mainly developed and maintainde by National Centre for Earth Observation and University of Reading.