t8dg (spoken as "tet-de-ge") is a C/C++ software to use a discontinuous galerkin method on adaptive meshes. t8dg uses t8code as a mesh managing library. It is licensed under the GNU General Public License 3.0 or later. Copyright (c) 2020 the developers.

We provide a short guide to install t8dg.

For a more detailed description, please see the Installation guide.

• libsc (Included in t8dg's git repository)
• p4est (Included in t8dg's git repository)
• t8code (Included in t8dg's git repository)
• automake
• libtool
• make

To setup the project perform the following steps

1.) If you cloned from github, initialize and download the git submodules
   t8code, p4est and sc.
  - git submodule init
  - git submodule update      
2.) Call the bootstrap script in the source directory
  - ./bootstrap        
3.) Goto your installation folder and call configure and make
  - cd /path/to/install
  - /path/to/source/configure [OPTIONS]
  - make 
  - make check
  - make install

To see a list of possible configure options, call

./configure -h

Most commonly used for t8dg are

--enable-mpi (enables MPI parallelization)

--enable-debug (enables debugging mode - massively reduces performance)

For a parallel release mode with local installation path $HOME/t8dg_install:

configure --enable-mpi CFLAGS=-O3 CXXFLAGS=-O3 --prefix=$HOME/t8dg_install

For a debugging mode with static linkage (makes using gdb and valgrind more comfortable):

configure --enable-mpi --enable-debug --enable-static --disable-shared CFLAGS="-Wall -O0 -g" CXXFLAGS="-Wall -O0 -g"

  1. configure and make as above
  2. Go to exec folder
    - cd /path/to/install
    - cd exec
  3. Call t8dg with -h flag to show possible options 
    - ./t8dg -h
  4. Call t8dg with appropriate options, for example with 
    - minimum refinement level 3, maximum refinement level 5 (-l3 -r5)
    - spatial and time integration order 4 (-L4 -o4)
    - CFL number = 0.05 (-C0.05) (can be chosen higher for smaller integration order)
    - square mesh (-m3)
    - and circular step function as initial condition (-i6):
    - ./t8dg -l3 -r5 -L4 -o4 -C0.05 -m3 -i6
  5. If t8dg is configured with MPI, call it with mpirun to execute in parallel:
    - mpirun -n 4 ./t8dg -l3 -r5 -L4 -o4 -C0.05 -m3 -i6
  6. t8dg produces the vtu files 't8dg_advection_*.{p}vtu'.
     To investigate, you can open the pvtu files in paraview.
     We suggest coloring for 'Num. Solution' and enabling 'Surface with edges'.

An (incomplete) list of publications related to t8dg:

[1] Lukas Dreyer, The local discontinuous galerkin method for the advection-diffusion equation on adaptive meshes, Master thesis at University of Bonn, 2021, Full text available

If you use t8dg in any of your publications, please cite the github repository and [1].