Building WarpX to use RZ geometry

WarpX can be built to run with RZ geometry. Both an FDTD solver (the default) and a PSATD solver are available. Both solvers allow multiple azimuthal modes.

To select RZ geometry, set the flag USE_RZ = TRUE when compiling:

make -j 4 USE_RZ=TRUE

Note that this sets DIM=2, which is required with USE_RZ=TRUE. The executable produced will have “RZ” as a suffix.

RZ geometry with spectral solver

Additional steps are needed to build the spectral solver. Some of the steps are the same as is done for the Cartesian spectral solver, setting up the FFTW package and setting USE_FFT=TRUE.

  • Install (or load) an MPI-enabled version of FFTW. For instance, for Debian, this can be done with

    apt-get install libfftw3-dev libfftw3-mpi-dev

  • Set the environment variable FFTW_HOME to the path for FFTW. For instance, for Debian, this is done with

    export FFTW_HOME=/usr/

  • Download and build the blaspp and lapackpp packages. These can be obtained from GitHub.

    git clone https://github.com/icl-utk-edu/blaspp.git
git clone https://github.com/icl-utk-edu/lapackpp.git

    The two packages can be built in multiple ways. A recommended method is to follow the cmake instructions provided in the INSTALL.md that comes with the packages. They can also be installed using spack.

  • Set the environment variables BLASPP_HOME and LAPACKPP_HOME to the locations where the packages libraries were installed. For example, using bash:

    export BLASPP_HOME=/location/of/installation/blaspp
export LAPACKPP_HOME=/location/of/installation/lapackpp

  • In some case, the blas and lapack libraries need to be specified. If needed, this can be done by setting the BLAS_LIB and LAPACK_LIB environment variables appropriately. For example, using bash:

    export BLAS_LIB=-lblas

  • Set USE_FFT=TRUE when compiling:

    make -j 4 USE_RZ=TRUE USE_FFT=TRUE