fhhos4

fhhos4 (pronounce 'phosphore') stands for Fast HHO Solver for Research. It is an open-source code that solves diffusion problems with the Hybrid High-Order (HHO) discretizations.

Features:

• solves diffusion problems with piecewise constant tensors
• HHO and DG discretizations
• high-order solutions
• handles unstructured meshes
• binded to the GMSH mesher
• implements geometric and algebraic multigrid methods
• exports linear systems
• shared-memory parallelism
• many parameters (various choices of polynomial bases, multigrid cycles, smoothers, coarsening strategies...)

The numerical experiments of related papers can be reproduced following the instructions in the reproducibility folder.

Install

This program depends on the following third-party software packages:

• Eigen
• CGAL (version 5.0 or later)
• GMSH (version 4.9.5 or later)

and optionally

• AGMG (version 3.3.5 or later).

Eigen and CGAL are header-only libraries, they are shipped with this code and will be compiled simultaneously with the program. So without the need for a specific version of those libraries, you have nothing to do. You can then skip step 1. Only GMSH is to be installed. To do so, follow step 2. Finally, build the program following step 4.

With conda, you can simply install the following packages in your environment:

conda install boost gmsh cgal cmake make

1. Install CGAL version 5.0 or later

(See https://doc.cgal.org/latest/Manual/usage.html)

Install with the package manager

sudo apt-get install libcgal-dev

or install with Spack (Spack installation steps here: https://spack-tutorial.readthedocs.io/en/latest/tutorial_basics.html)

spack install cgal
spack load cgal 

or install with the sources

mkdir cgal && cd cgal   # create it wherever you want
wget https://github.com/CGAL/cgal/releases/download/v5.1/CGAL-5.1.tar.xz
tar xf CGAL-5.1.tar.xz  # the path to CGAL must then be added to the cmake command via -DCGAL_DIR=<path>/cgal/CGAL-5.1

2. Install GMSH version 4.9.5 or later

(See http://gmsh.info/#Download)

mkdir gmsh && cd gmsh      # create it wherever you want
wget gmsh.info/src/gmsh-4.9.5-source.tgz
tar zxvf gmsh-4.9.5-source.tgz
cd gmsh-4.9.5-source/
mkdir build && cd build
cmake -DENABLE_BUILD_DYNAMIC=1 -DENABLE_FLTK=0 .. # if issue with cgns, add option -DENABLE_CGNS=0 
make                       # and go get a coffee

3. Install AGMG version 3.3.5 or later (optional)

AGMG must be compiled to get the .o files

mkdir agmg && cd agmg     # create it wherever you want
mv <path>/AGMG_3.3.5-aca.for.tar.gz .
tar -xvf AGMG_3.3.5-aca.for.tar.gz
cd AGMG_3.3.5-aca/Example_seq/
make                      # the .o files should be in the SRC/ directory

4. Use CMake to build fhhos4

cd <path-to-fhhos4>
mkdir build && cd build
cmake -DCMAKE_BUILD_TYPE=Release -DGMSH_API=<path>/gmsh/gmsh-9.5.0-source/api -DGMSH_LIB=<path>/gmsh/gmsh-4.9.5-source/build/libgmsh.so -DENABLE_AGMG=ON -DAGMG_DIR=<path>/agmg/AGMG_3.3.5-aca/SRC ..
make

5. Launch help command to view arguments and examples

./bin/fhhos4 -h

Troubleshooting

1. Could NOT find GMP

CMake Error at /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
  Could NOT find GMP (missing: GMP_LIBRARIES GMP_INCLUDE_DIR)
Call Stack (most recent call first):
  /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:378 (_FPHSA_FAILURE_MESSAGE)
  dependencies/cgal/CGAL-5.1/cmake/modules/FindGMP.cmake:53 (find_package_handle_standard_args)
  dependencies/cgal/CGAL-5.1/cmake/modules/CGAL_SetupGMP.cmake:24 (find_package)
  dependencies/cgal/CGAL-5.1/cmake/modules/CGAL_SetupCGALDependencies.cmake:41 (include)
  dependencies/cgal/CGAL-5.1/lib/cmake/CGAL/CGALConfig.cmake:128 (include)
  dependencies/cgal/CGAL-5.1/CGALConfig.cmake:6 (include)
  CMakeLists.txt:64 (find_package)

Install GMP:

sudo apt-get install libgmp-dev

2. Could NOT find MPFR

CMake Error at /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
  Could NOT find MPFR (missing: MPFR_LIBRARIES MPFR_INCLUDE_DIR)
Call Stack (most recent call first):
  /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:378 (_FPHSA_FAILURE_MESSAGE)
  dependencies/cgal/CGAL-5.1/cmake/modules/FindMPFR.cmake:52 (find_package_handle_standard_args)
  dependencies/cgal/CGAL-5.1/cmake/modules/CGAL_SetupGMP.cmake:25 (find_package)
  dependencies/cgal/CGAL-5.1/cmake/modules/CGAL_SetupCGALDependencies.cmake:41 (include)
  dependencies/cgal/CGAL-5.1/lib/cmake/CGAL/CGALConfig.cmake:128 (include)
  dependencies/cgal/CGAL-5.1/CGALConfig.cmake:6 (include)
  CMakeLists.txt:64 (find_package)

Install MPFR:

sudo apt-get install libmpfr-dev

You might also need to install boost:

sudo apt-get install libboost-all-dev