Merlin - Compression And Interpolation Of Nuclear Homogenized Cross Section Data

The Merlin project aims to provide a simple data processing framework for few-group homogenized cross sections dataset, which is utilized in industrial reactor simulation and reactor research projects. It is an independent, portable, and scalable library written in modern C++20 and CUDA, with a Python interface installable with pip.

Merlin consists of two main libraries: candy for compression and decompression of the cross section dataset with tensor decomposition by the gradient-based approach of CANDECOMP-PARAFAC, and splint for interpolation of the reconstructed tensor by linear or polynomial interpolation.

Merlin is optimized with many optimization techniques, including vectorization with AVX and parallelization on both CPU and multi-GPUs systems, to expedite its algorithms.

Installation

C++/CUDA library

Prior to installing, please ensure these prerequisites:

• gcc>=11.2 (on Linux)
• MSVC 2022 cl.exe>=19.39 (on Windows)
• CUDA nvcc>=12.1 (if compiling library for GPU)
• CMake not older than 3.25
• Build system: GNU make for Linux, or Ninja for Windows

Configuration and compilation:

cmake --preset=linux .  # switch to --preset=windows to compile with MSVC
cd build
# ninja  # for Windows
make -j 8

Installation:

cmake --install . --prefix="/path/to/install folder"

Due the restriction of the CUDA compiler nvcc, Merlin can only be compiled using gcc on Linux or MSVC 2022 on Windows. Other compilers such as clang on Mac OS, or Intel compiler icc, will raise compilation errors with Merlin.

Python interface

Python interface requires the compiled C++/CUDA library. It enables calling C++/CUDA functions and classes from Python scripts through Pybind11.

pip install .

To compile the Python interface "inplace" (binary module copied to the source directory):

python setup.py build_ext -i

Documentation

Required Sphinx extensions:

pip install -U sphinx_rtd_theme sphinx_design breathe sphinx_doxysummary

Code documentation can be built with Doxygen and Sphinx:

cd docs
doxygen Doxyfile
make html  # or .\make.bat html on Windows

License

This project is subject to the MIT License.