• MagIC is a numerical code that can simulate fluid dynamics in a spherical shell. MagIC solves for the Navier-Stokes equation including Coriolis force, optionally coupled with an induction equation for Magneto-Hydro Dynamics (MHD), a temperature (or entropy) equation and an equation for chemical composition under both the anelastic and the Boussinesq approximations.

• MagIC uses either Chebyshev polynomials or finite differences in the radial direction and spherical harmonic decomposition in the azimuthal and latitudinal directions. The time-stepping scheme relies on a semi-implicit Crank-Nicolson for the linear terms of the MHD equations and a Adams-Bashforth scheme for the non-linear terms and the Coriolis force.

• MagIC is written in Fortran and designed to be used on supercomputing clusters. It thus relies on a hybrid parallelisation scheme using both OpenMP and MPI. Postprocessing functions written in python (requiring matplotlib and scipy are also provided to allow a useful data analysis.

• MagIC is a free software. It can be used, modified and redistributed under the terms of the GNU GPL v3 licence.

$ git clone https://github.com/magic-sph/magic.git

or via SSH (it requires a public key):

$ git clone ssh://[email protected]/magic-sph/magic.git

$ cd magic

If you are using sh, bash or zsh as default shell (echo $SHELL), just use the command

$ source sourceme.sh

If you are using csh or tcsh, then use the following command

$ source sourceme.csh

Create a directory where the sources will be built

$ mkdir $MAGIC_HOME/build
$ cd $MAGIC_HOME/build

Set up your compilers

$ export FC=mpiifort
$ export CC=mpiicc

Compile and produce the executable (options can be passed to cmake using -DOPTION=value)

$ cmake ..
$ make -j

The executable magic.exe has been produced!

Go to the source directory

$ cd $MAGIC_HOME/src

Edit the Makefile with your favourite editor and specify your compiler (intel, gnu, portland) and additional compiler options (production run or not, debug mode, MKL library, ...)

$ make -j

The executable magic.exe has been produced!

$ cd $MAGIC_HOME/samples
$ ./magic_wizard.py --use-mpi --nranks 4 --mpicmd mpiexec

If everything is correctly set, all auto-tests should pass!

$ cd $SCRATCHDIR/run
$ cp $MAGIC_HOME/build/magic.exe .
$ cp $MAGIC_HOME/samples/hydro_bench_anel/input.nml .

Then change the input namelist to the setup you want and run the code:

$ export OMP_NUM_THREADS=2
$ export KMP_AFFINITY=verbose,granularity=core,compact,1
$ mpiexec -n 4 ./magic.exe input.nml

a) Set-up your PYTHON environment (ipython, scipy and matplotlib are needed)

b) Modify magic.cfg according to your machine in case the auto-configuration didn't work

$ vi $MAGIC_HOME/python/magic/magic.cfg

c) You can now import the python classes:

python> from magic import *

and use them to read time series, graphic files, movies, ...

python> ts = MagicTs(field='e_kin', all=True)
python> s = Surf()
python> s.equat(field='vr')
python> ...

a) Before commiting your modifications always make sure that the auto-tests pass correctly.

b) Try to follow the same coding style rules as in the rest of the code:

1. Never use TABS but always SPACES instead
2. Use 3 spaces for indentation
3. Never use capital letters for variable declaration or Fortran keywords
4. Never use dimension(len) for declaring array but rather real(cp) :: data(len)
5. Always use the default precisions when introducing new variables (cp)

More on that topic here

• Boussinesq equations: Wicht (2002, PEPI, 132, 281-302)
• Anelastic equations: Gastine & Wicht (2012, Icarus, 219, 428-442)
• In case you use the SHTns library for the spherical harmonics transforms (MagIC 5.3 or later), please also cite: Schaeffer (2013, GGG, 14, 751-758)

MagIC has been tested and validated against several international dynamo benchmarks:

• Christensen et al. (2001, PEPI, 128, 25-34)
• Breuer et al. (2010, GJI, 183, 150-162)
• Jones et al. (2011, Icarus, 216, 120-135)