Level Set Method Library (LSMLIB)

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Announcement

• (May 2022) LSMLIB v2.0.x is intended to be a stable version of LSMLIB that can serve as a foundation for specialized applications and packages. The library has been refactored and only includes support for serial computations implemented in C/C++ (the parallel LSMLIB and Python interfaces have been moved to their own separate codebases and repositories). There are currently no plans to further develop LSMLIB parallel LSMLIB or the Python interface.

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Table of Contents

1. Overview

   1.1. Package Contents

   1.2. Software Dependencies

   1.3. License

2. Installation

   2.1. Building the Package

   2.2. Running Tests

   2.3. Installing the Package

   2.4. Uninstalling the Package

3. Known Issues

4. Acknowledgments

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1. Overview

The Level Set Method Library (LSMLIB) provides support for simulation of implicit surface and curve dynamics in two- and three-dimensions. It contains an implementation of the basic level set method algorithms and numerical kernels described in "Level Set Methods and Dynamics Implicit Surfaces" by S. Osher and R. Fedkiw and "Level Set Methods and Fast Marching Methods" by J.A. Sethian. It also contains implementations of several advanced level set method techniques available in the literature.

The library consists of a collection of Fortran subroutines and C/C++ functions. The main features of the library include:

• high-computational and high-programmer performance through the use of mixed-language programming (e.g. C++/Fortran77, C/Fortran77);

• support for narrow-band/localized computation.

1.1. Package Contents

LSMLIB contains a collection of numerical kernels that are commonly used in level set method calculations. It currently provides numerical kernels for the following:

• computation of spatial derivatives using high-order ENO/WENO schemes

• TVD Runge-Kutta time integration schemes

• imposing boundary conditions

• computation of a variety of geometric quantities (e.g. normal, area/volume, curvature, etc.)

• integration over regions defined by implicit functions

• computing the right-hand side of specific level set method partial differential equations;

• localization/narrow-band calculations

• fast marching method calculations (e.g. signed distance function, solution to Eikonal equation); and

• mathematical functions (e.g. delta functions, norms, etc.).

In addition, LSMLIB provides several utility functions for

• managing of computational grids and data,

• initializing level set functions for simple geometries,

• imposing boundary conditions,

• computing signed distance functions and extension fields via the fast marching method,

• carrying out common data manipulations (e.g. copying data, computing the norm of a grid function).

1.2. Software Dependencies

• Compilers: C, C++, Fortran

1.3. License

See the LICENSE file for copyright and license information.

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2. Installation

2.1. Building the Package

• Create a build directory, and change into it.

  $ mkdir build
  $ cd build

• Generate the build files.

  $ cmake ..

• Build the package.

  $ make

2.2. Running Tests

• From the build directory, use make tests to build the unit tests.

  $ make tests

• From the build directory, use ctest or make test to run the unit tests.

  $ ctest

  For a more detailed test report, use ctest --verbose.

  $ ctest --verbose

2.3. Installing the Package

• Set the installation location for the package.

  $ cd build
  $ cmake -DCMAKE_INSTALL_PREFIX=/PATH/TO/INSTALL/LOCATION ..

  Note: the -DCMAKE_INSTALL_PREFIX option could have been included in the command used when generating the build files.

• Use make install to install the package.

  $ make install

• (OPTIONAL) Remove the build directory.

2.4. Uninstalling the Package

• To uninstall the package, use make uninstall from within the build directory.

  $ cd build
  $ make uninstall

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3. Known Issues

• Several of the numerical kernels lack unit tests.

• The package only supports one-, two-, and three-dimensional calculations.

• Adapative mesh refinement is not yet available.

• Computation of the maximum stable time step is incorrect for problems involving both advection and motion in the normal direction.

• There are a few warnings that show up when using strict compilers (e.g. Intel Compilers). These are primarily a result of not explicitly dealing with return values from standard C library functions and do not lead to any numerical inaccuracies.

• We do not officially support Windows at this time.

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4. Acknowledgments

The LSMLIB developers gratefully acknowledge support from the following funding agencies:

• Department of Energy under contract numbers DE-FG02-97ER25308 (Computational Science Graduate Fellowship) and DE-FC26-06NT43067

• Department of Agriculture under grant #2007-35102-18162

• National Science Foundation

• Air Force Office of Scientific Research

We would also like to thank the following individuals:

• Professor David J. Srolovitz (Yeshiva University) and Professor Steven L. Bryant (University of Texas at Austin) - support and encouragement in developing LSMLIB

• Zhaoxuan Wu - original autoconf system for building LSMLIB

• Xiaohai Wan, Thomas Pintelon, and Ning Zhang - documentation for building LSMLIB on Windows

• Contributing Users/Bug Reporters: Daniel Thorpe, Markus Gross, Anatoliy Kats, Yi Li, Guillaume Walck and his students, Burak Ozkalayci, Zhang Ning, Stefan Sokoll, Moslem Kazemi, Danping Zou, Marc Day, and Ruhollah Tavakoli.

• Our humblest apologies if we have accidentally left anybody off of this list. Please let us know and we will remedy the situation immediately.

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