Spiner

Performance portable utilities for representing and interpolating tabulated data. Named for Brent Spiner. For full documentation, see here.

Performance portability

Spiner is compatible with code on CPU, GPU, and everything in between. We use ports-of-call for this feature.

Building and Installation

Spiner is header-only and requires C++20, CMake 3.24 or newer, and Ports-of-Call 3.1.1 or newer. Clone it as

git clone --recursive git@github.com:lanl/spiner.git

To build and run unit tests,

cd spiner
cmake -S . -B bin -DSPINER_BUILD_TESTS=ON -DSPINER_TEST_USE_KOKKOS=OFF
cmake --build bin --parallel 6
ctest --test-dir bin --output-on-failure -j 6

and to do convergence testing,

cmake --build bin --target convergence --parallel 6

after building.

To install,

cmake --install bin --prefix /path/to/install

after configuring and building.

Build options

• SPINER_USE_HDF enables or disables HDF5. Default is OFF
• SPINER_TEST_USE_KOKKOS enables Kokkos for tests; defaults to ON when tests are enabled.
• SPINER_TEST_USE_KOKKOS_CUDA enables CUDA for the fetched test Kokkos; default is ON.
• SPINER_USE_PORTABLE_NQT selects portable NQT functions; default is OFF.
• SPINER_BUILD_TESTS enables or disables tests. Default is OFF. If this is disabled, then configuration only prepares for install and provides targets for in-tree builds, as no build step is necessary.
• CMAKE_PREFIX_PATH supplies installation prefixes for dependency discovery.
• FETCHCONTENT_SOURCE_DIR_<NAME> supplies an existing dependency source tree, for example FETCHCONTENT_SOURCE_DIR_KOKKOS.

Including spiner in your project

You can build spiner in-line with your project, or pre-install it. It's header-only and the include directories should have the expected structure. If you build inline, add the following target to your cmake:

target_link_libraries(my_project PRIVATE spiner::spiner)

Dependencies

Spiner relies on ports-of-call 3.1.1 or newer for performance portability. CMake first searches installed packages and fetches the pinned dependency when no compatible package is found. When integrating without CMake, provide both the complete spiner/ header directory and Ports-of-Call headers.

The testing tooling requires a few different pieces:

• Unit testing requires Catch2, which is downloaded automatically if needed.
• Convergence testing requires the scientific python stack, including:
  • python3
  • numpy
  • matplotlib

HDF5

Spiner supports reading and writing DataBox objects into a custom HDF5 format called SP5. To enable this, compile with the appropriate HDF5 linking and the flag -DSPINER_USE_HDF. If you use the cmake build system, just configure with -DSPINER_USE_HDF=ON.

CUDA and Kokkos

Spiner uses Ports-of-Call for portability. Test builds can use an installed Kokkos discovered through CMAKE_PREFIX_PATH, or fetch Kokkos automatically. For CUDA tests, configure with an appropriate CUDA compiler wrapper:

cmake -S . -B bin-cuda -DSPINER_BUILD_TESTS=ON \
  -DSPINER_TEST_USE_KOKKOS=ON -DSPINER_TEST_USE_KOKKOS_CUDA=ON \
  -DCMAKE_CXX_COMPILER=nvcc_wrapper
cmake --build bin-cuda --parallel 6
ctest --test-dir bin-cuda --output-on-failure -j 6

Set the appropriate Kokkos architecture options for your hardware. For CPU Kokkos tests, set SPINER_TEST_USE_KOKKOS_CUDA=OFF.

Clang-Format

Clang-format version 19 is required for committing, and a github workflow is used to check that code meets format requirements. We provide a make target in the build system. After configuration, simply type

cmake --build bin --target format_spiner --parallel 6

to format the code.

Other versions of clang-format may work. If you would like to try, please examine the diff and see if the formatting appears stable. Otherwise, you may need to upgrade your version of clang-format.

In general, we recommend formatting regularly so that the format calls do not pollute the diffs. If a format call necessarily pollutes the diff, do it as a separate commit.

Features

• Spiner supports interpolation in arbitrary dimensions, and it's fast in 3d and fewer.
• Spiner supports interpolation onto "subtables"

Interpolation

Interpolation is linear by default. For values and analytic derivatives in 1D and 2D, interpToRealWithGrads also supports the Spiner::InterpolationStencils::Rational policy. See the rational interpolation documentation for policy selection, the four-point minimum per axis, and boundary behavior. Value-only interpToReal calls remain linear.

Here's an example of linear interpolation in 3D (2D slice shown). Convergence is second-order, as expected.

Interpolation is fast and portable. Here's performance on several different problem sizes and several different architectures with different parallelism strategies:

Contributing

If you use Spiner and need help, submit an issue to the Spiner repository. If you'd like to contribute, just fork and submit a pull request. There's a check list in the PR template, and one of the main Spiner developers will review your PR.

Contributors

Spiner was primarily developed by Jonah Miller in collaboration with

• Chad Meyer
• Daniel Holladay
• Josh Dolence
• Sriram Swaminarayan

Continuous integration and build system support has been provided by

• Jonah Miller
• Karen Tsai
• Christopher Mauney

Copyright

Generative AI was used to assist with modifications to this document.

© (or copyright) 2019-2026. Triad National Security, LLC. All rights reserved. This program was produced under U.S. Government contract 89233218CNA000001 for Los Alamos National Laboratory (LANL), which is operated by Triad National Security, LLC for the U.S. Department of Energy/National Nuclear Security Administration. All rights in the program are reserved by Triad National Security, LLC, and the U.S. Department of Energy/National Nuclear Security Administration. The Government is granted for itself and others acting on its behalf a nonexclusive, paid-up, irrevocable worldwide license in this material to reproduce, prepare derivative works, distribute copies to the public, perform publicly and display publicly, and to permit others to do so.

This program is open source under the BSD-3 License. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

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