Installation

Requirements

C++17 compiler (GCC 7+, Clang 5+, MSVC 2017+)
CMake 3.15 or later
Eigen 3.4 (fetched automatically via CMake FetchContent)

Optional:

pybind11 2.13+ (fetched automatically when building Python bindings)
OpenMP (detected automatically; enables parallel spectral loops)
Python 3.8+ with NumPy (for using the Python interface)

Building the C++ library

cd DisORT
mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make -j$(nproc)

CMake will download Eigen 3.4 into build/_deps/ on the first build. Subsequent builds reuse the cached download.

The build produces the static library libdisortpp.a and the test executable tests/disortpp_tests.

Build options

Option	Default	Description
`CMAKE_BUILD_TYPE`	`Release`	`Release` (`-O3 -march=native`) or `Debug` (`-g -Wall`)
`BUILD_PYTHON_BINDINGS`	`OFF`	Build the `disortpp` Python module via pybind11

Building with Python bindings

cd DisORT
mkdir build && cd build
cmake .. -DBUILD_PYTHON_BINDINGS=ON -DCMAKE_BUILD_TYPE=Release
make -j$(nproc)

This additionally produces the shared library disortpp.cpython-3XX-x86_64-linux-gnu.so (the exact filename depends on your Python version and platform).

To use the module, either run Python from the build/ directory or add it to PYTHONPATH:

export PYTHONPATH=/path/to/DisORT/build:$PYTHONPATH
python3 -c "import disortpp; print('OK')"

Running the tests

cd build
ctest --output-on-failure

Or run the test binary directly for verbose output:

./tests/disortpp_tests

Using DisORT++ in your CMake project

Add DisORT++ as a subdirectory or use FetchContent:

add_subdirectory(DisORT)

add_executable(my_app main.cpp)
target_link_libraries(my_app PRIVATE disortpp)

The disortpp target transitively provides the Eigen include directories, so no additional find_package(Eigen3) call is needed.