Configuring SWIFT with VELOCIraptor
In the following three paragraphs we will explain how to setup VELOCIraptor, how to compile it and how to compile SWIFT with VELOCIraptor.
Setting up VELOCIraptor
Before we can run SWIFT with VELOCIraptor we first need to download VELOCIraptor. This can be done by cloning the repository on GitHub:
git clone https://github.com/ICRAR/VELOCIraptor-STF.git
The SWIFT interface is in the master branch of VELOCIraptor so nothing is more is needed besides fetching the latest version of the NBodyLib that the code relies upon:
cd VELOCIraptor-STF git submodule update --init --recursive
To get VELOCIraptor working with SWIFT simply use:
mkdir build cd build cmake ../ -DVR_USE_HYDRO=ON -DVR_USE_SWIFT_INTERFACE=ON -DCMAKE_CXX_FLAGS="-fPIC" -DCMAKE_BUILD_TYPE=Release
The first parameter activates the processing of gas, stars and black holes. It can be omitted for simulations evolving only dark matter.
If you wish to run swift without MPI, you will need to add
After we downloaded the files and made a configuration file we can compile VELOCIraptor as follows:
After the compilation of your code, you will find a static library
that is required to run SWIFT with VELOCIraptor.
Note that VELOCIraptor needs a serial version of the
HDF5 library, not a parallel build.
The next part is compiling SWIFT with VELOCIraptor and assumes you already downloaded SWIFT from the GitLab repository. This can be done by running
./autogen.sh ./configure --with-velociraptor=/path/to/VELOCIraptor-STF/build/src make
./autogen.sh only needs to be run once after the code is cloned
from the GitLab, and
/path/to/ is the path to the
directory on your machine. Note that this path must be absolute (i.e. relative
/, if you want to run the MPI version of VELOCIraptor as well as a
non-MPI one with the same version of SWIFT, then you will need to compile
VELOCIraptor twice and create two builds, then use the
--with-velociraptor-mpi configure option to point to the MPI build and the
--with-velociraptor option to point at the non-MPI build.
./configure can be run with other options as desired.
If you see reports about missing references to
similar functions, then you will also need to include the C++ version
of the MPI library in
LIBS variable as part of the configuration
(or by setting the
LIBS environment variable), as in:
./configure --with-velociraptor=/path/to/VELOCIraptor-STF/build/src LIBS=-lmpi++
other names and libraries may be necessary as these are MPI flavour determined.
After this we can run SWIFT with VELOCIraptor, but for this we first need to add several lines to the yaml file of our simulation
StructureFinding: config_file_name: vrconfig_3dfof_subhalos_SO_hydro.cfg basename: haloes scale_factor_first: 0.02 delta_time: 1.02
In which we specify the
.cfg file that is used by VELOCIraptor and the
other parameters which SWIFT needs to use. In the case of
the Small Cosmological Volume DMO example we can run a simulation with halo
cd examples/SmallCosmoVolume_DM ../swift --cosmology --hydro --self-gravity --velociraptor --threads=8 small_cosmo_volume_dm.yml
Which activates the VELOCIraptor interface.