AxiSEM3D - A Quickstart Guide

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1 Get AxiSEM3D

git clone https://github.com/kuangdai/AxiSEM3D
export CURRENT_WORK_DIR=$PWD

2 Installing dependencies

AxiSEM3D has been built upon a few modern numerical packages for its performance and sustainability, as listed below (newer versions are acceptable):

name	version	build-from-source instructions
MPI	---	Common implementations such as open-mpi or mpich2.
Boost	1.60	Simply download and unzip to your path of treasures. No need to build or install.
Eigen3	3.3-rc1	Simply download and unzip to your path of treasures. No need to build or install.
FFTW	3.3	Install both double-precision (without --enable-float) and single-precision (with --enable-float) versions to the same path. See here.
METIS	5.1	Download and install following Install.txt. Skip step 3 in Install.txt to use the 32-bit build.
NetCDF	4.4	Follow instructions here. To avoid compatibility issues, AxiSEM3D does not directly use HDF5, the major dependency of NetCDF4.

Don't panic! All these popular packages may be handily installed with free package management software, such as Conda. Here we introduce the wizard axisem3d_depends.sh.

• Make sure your MPI works properly.
• Get Conda.
• Edit the first few lines in axisem3d_depends.sh and run it.
• Check your ~/.bash_profile (or ~/.bashrc) and ~/.axisem3d_roots. Grats, you are done!

3 Building AxiSEM3D

• Edit SOLVER/CMakeLists.txt if needed (normally not), including

  to-be-edited	notes
  compiler suit	Changes are usually required only for HPC clusters, unless you have a bizarre MPI.
  dependency roots	No need if you have used axisem3d_depends.sh to install the dependencies.
  FFTW_WISDOM_DIR	Just specify any directory you like, or leave it as it.

• Build AxiSEM3D (go step by step to see what's happening)

  • Style 1: work under source

    cd $CURRENT_WORK_DIR/AxiSEM3D
    # make a simulation directory
    mkdir my_first_run
    cd my_first_run
    # cmake (*** see the notes below ***)
    cmake -DCMAKE_BUILD_TYPE=release ../SOLVER
    # compile and link
    make -j4
    # copy the input folder
    cp -R ../template/input ./
    # run it with any number of processors
    mpirun -np 4 ./axisem3d
    # check the outputs
    ls output

    Read the output of cmake carefully, which should end up with (If not, verify dependency installations as prompted)

    -- Configuring done
    -- Generating done
    -- Build files have been written to: ...

  • Style 2: keep source clean (suggested)

    To offer maximal flexibility for various infrastructures, AxiSEM3D is organized such that the directories of source, build and simulations are fully independent of one another. For exmaple:

    ########## build ##########
    cd $CURRENT_WORK_DIR
    # make a build directory
    mkdir my_axisem3d_build
    cd my_axisem3d_build
    # cmake
    cmake -DCMAKE_BUILD_TYPE=release ../AxiSEM3D/SOLVER
    # compile and link
    make -j4
    
    ########## run ##########
    # make a simulation directory
    cd $CURRENT_WORK_DIR
    mkdir my_second_run
    cd my_second_run
    # copy the executable 
    cp ../my_axisem3d_build/axisem3d ./
    # copy the input folder
    cp -R ../AxiSEM3D/template/input ./
    # Though optional, it is always a good practice 
    # to backup the source code for reproducibility:
    cp -r ../AxiSEM3D/SOLVER ./
    # run it with any number of processors
    mpirun -np 4 ./axisem3d
    # check the outputs
    ls output

4 The MESHER

In the above examples, we use the mesh file AxiSEM_prem_ani_one_crust_50.e (anisotropic PREM model with one crustal layer at a 50 s period), located at SOLVER/template/input.

To generate an AxiSEM3D mesh like this, you will need the salvus_mesher_lite, a python-based command-line tool to generate AxiSEM/AxiSEM3D meshes (credit to van Driel Martin, Lion Krischer and others from the Salvus group at ETH Zurich).

• See installation and usage of salvus_mesher_lite from here.