Installation

pip install

Python versions supported - 3.8, 3.9 and 3.10

You can install gfs_dynamical_core using the command. This should also automatically install the correct version of climt.

$ pip install gfs_dynamical_core

Working versions - 0.1.23 and 0.1.9

Specify the version if required

$ pip install gfs-dynamical-core==0.1.23

On Ubuntu Linux, you might need to prefix the above command with sudo. This command should work on Linux and Mac. This package is currently not available on Windows.

Note

If you are not using Anaconda, please ensure you have the libpython library installed.

This is the simplest way to install the gfs_dynamical_core package and does not require a compiler on your system. However, as pip installs wheels for a generic system architecture, installing via pip will not build optimally for your particular architecture, resulting in a slower code.

For this reason, it is recommended to build gfs_dynamical_core from source.

If you don’t have pip installed, this Python installation guide can guide you through the process.

Installing from source

The sources for gfs_dynamical_core can be downloaded from the Github repo.

To clone the public repository:

$ git clone https://github.com/Ai33L/gfs_dynamical_core.git

Once you have a copy of the source, you can install it from inside the gfs_dynamical_core directory with:

$ pip install -r requirements_dev.txt
$ python setup.py develop

Both commands may require the use of sudo.

Dependencies for source installations

gfs_dynamical_core depends on some easily installable libraries. For an installation from source, it also requires that C and fortran compilers be installed.

On Ubuntu Linux, for example, these dependencies can be installed by:

$ sudo apt-get install gcc
$ sudo apt-get install gfortran
$ sudo apt-get install python-dev
$ sudo pip install -U cython
$ sudo pip install -U numpy

use pip3 and python3-dev if you use Python 3.

On Mac OSX, it is recommended that you use anaconda as your python distribution. This will eliminate the need to install cython, numpy and python-dev. Once you have anaconda installed, you will need to do the following:

$ brew install gcc
$ export CC=gcc-x
$ export FC=gfortran-x

Where gcc-x,gfortran-x are the names of the C,Fortran compilers that Homebrew installs. Exporting the name of the compiler is essential on Mac since the default compiler that ships with Mac (called gcc, but is actually a different compiler) cannot compile OpenMP programs.

Common build issues

A frequent issue is OpenBLAS build failing. This happens when OpenBLAS fails to detect cpu architecture and/or if a particular cpu is not supported. If you face this issue, modify line 64 in gfs_dynamical_core/_lib/Makefile

if [ ! -d $(BLAS_DIR) ]; then mkdir $(BLAS_DIR); tar -xvzf $(BLAS_GZ) -C $(BLAS_DIR) --strip-components=1 > log 2>&1; fi; cd $(BLAS_DIR); CFLAGS=$(CLIMT_CFLAGS) make NO_SHARED=1 NO_LAPACK=0 > log 2>&1 ; make PREFIX=$(BASE_DIR) NO_SHARED=1 NO_LAPACK=0 install > log.install.blas 2>&1 ; cp ../lib/libopenblas.a $(LIB_DIR)

Modify this to

if [ ! -d $(BLAS_DIR) ]; then mkdir $(BLAS_DIR); tar -xvzf $(BLAS_GZ) -C $(BLAS_DIR) --strip-components=1 > log 2>&1; fi; cd $(BLAS_DIR); CFLAGS=$(CLIMT_CFLAGS) make TARGET='GENERIC' NO_SHARED=1 NO_LAPACK=0 > log 2>&1 ; make PREFIX=$(BASE_DIR) NO_SHARED=1 NO_LAPACK=0 install > log.install.blas 2>&1 ; cp ../lib/libopenblas.a $(LIB_DIR)

Speciying a GENERIC architecture will not optimise for the specific architecture, but should solve the build issue in most cases.