SymEngine

SymEngine is a standalone fast C++ symbolic manipulation library. Optional thin wrappers allow usage of the library from other languages, e.g.:

• C wrappers allow usage from C, or as a basis for other wrappers (the symengine/cwrapper.h file)
• Python wrappers allow easy usage from Python and integration with SymPy and Sage (the symengine/python directory)
• Ruby wrappers (the symengine/ruby directory)
• Julia wrappers (the SymEngine.jl repository)
• ...

License

All files are licensed under MIT license, see the LICENSE for more information. The src/teuchos directory is licensed under the Trilinos BSD license (see the LICENSE file).

Mailinglist, Chat

We use the SymPy mailinglist: http://groups.google.com/group/sympy


Installation

Install prerequisites. For Debian based systems (Ubuntu etc.):

apt-get install cmake libgmp-dev

For RPM based systems (Fedora etc.):

yum install cmake gmp-devel

Install SymEngine:

cmake .
make

This will configure and build SymEngine in the default Release mode with all code and compiler optimizations on.

Run tests:

ctest

Python Wrappers

The optional Python wrappers can be turned on by

cmake -DWITH_PYTHON=yes .
make

Use SymEngine from Python as follows:

>>> from symengine import var
>>> var("x y z")
(x, y, z)
>>> e = (x+y+z)**2
>>> e.expand()
2*x*y + 2*x*z + 2*y*z + x**2 + y**2 + z**2

You can read Python tests in symengine/tests to see what features are implemented. Supported versions of Python are: 2.6, 2.7, 3.2, 3.3. You need Cython >= 0.19.1 in order to compile the wrappers. CMake will report at configure time if the Cython version is too old.

Development

The Travis-CI checks the code in both Release and Debug mode with all possible checks, so just sending a GitHub pull request is enough and you can use any mode you want to develop it. However, the best way to develop SymEngine is to use the Debug mode with BFD support on:

cmake -DCMAKE_BUILD_TYPE=Debug -DWITH_BFD=yes .

This BFD support turns on nice Python like stacktraces on exceptions, assert errors or segfaults, and the Debug mode automatically turns on WITH_SYMENGINE_RCP=no (which uses Teuchos::RCP with full Debug time checking) and WITH_SYMENGINE_ASSERT=yes, so the code cannot segfault in Debug mode, as long as our style conventions (e.g. no raw pointers) are followed, which is easy to check by visual inspection of a given Pull Request. In Release mode, which is the default, the code is as performing as manual reference counting and raw pointers (and if there is a bug, it could segfault, in which case all you have to do is to turn Debug mode on and get a nice exception with a stacktrace).

To make WITH_BFD=yes work, you need to install binutils-dev first, otherwise you will get a CMake error during configuring. For Debian based systems (Ubuntu etc.)

apt-get install binutils-dev

For RPM based systems (Fedora etc.)

yum install binutils-devel

CMake Options

Here are all the CMake options that you can use to configure the build, with their default values indicated below:

cmake -DCMAKE_INSTALL_PREFIX:PATH="/usr/local" \  # Installation prefix
    -DCMAKE_BUILD_TYPE:STRING="Release" \         # Type of build, one of: Debug or Release
    -DWITH_BFD:BOOL=OFF \                         # Install with BFD library (requires binutils-dev)
    -DWITH_PYTHON:BOOL=OFF \                      # Build Python wrappers
    -DWITH_SYMENGINE_ASSERT:BOOL=OFF \            # Test all SYMENGINE_ASSERT statements in the code
    -DWITH_SYMENGINE_RCP:BOOL=ON \                # Use our faster special implementation of RCP
    -DWITH_SYMENGINE_THREAD_SAFE:BOOL=OFF \       # Build with thread safety
    -DWITH_ECM:BOOL=OFF \                         # Build with GMP-ECM library for integer factorization
    -DWITH_PRIMESIEVE:BOOL=OFF \                  # Install with Primesieve library
    -DWITH_ARB:BOOL=OFF \                         # Install with ARB library
    -DWITH_TCMALLOC:BOOL=OFF \                    # Install with TCMalloc linked
    -DWITH_OPENMP:BOOL=OFF \                      # Install with OpenMP enabled
    -DWITH_PIRANHA:BOOL=OFF \                     # Install with Piranha library
    -DBUILD_TESTS:BOOL=ON \                       # Build with tests
    -DBUILD_BENCHMARKS:BOOL=ON \                  # Build with benchmarks
    .

If OPENMP is enabled, then SYMENGINE_THREAD_SAFE is also enabled automatically irrespective of the user input for WITH_SYMENGINE_THREAD_SAFE.

CMake prints the value of its options at the end of the run. If you want to use a different compiler, do:

CC=clang CXX=clang++ cmake .

and check that CMake picked it up.

External Libraries

There are three ways how to specify where external libraries are. In the lines below, change PKG1, PKG2, ... to the names of the external libraries (GMP, ARB, PRIMESIEVE, BFD, FLINT, MPFR, ...).

1. cmake -DPKG1_DIR=$HASHSTACK -DPKG2_DIR=$HASHSTACK .
2. cmake -DPKG1_INCLUDE_DIRS=$HASHSTACK/include -DPKG1_LIBRARIES=$HASHSTACK/lib -DPKG2_DIR=$HASHSTACK .
3. cmake -DCOMMON_DIR=$HASHSTACK .

In the approach 1., you specify PKG_DIR as the base prefix, and the include files must be in ${PKG_DIR}/include and libraries in ${PKG_DIR}/lib (or lib64). In the approach 2., you specify the include and library directories separately (you can use approach 1. for some libraries and 2. for other libraries on the same command line). In the approach 3., you specify a common prefix for all libraries at once.

If all your libraries are installed in the same prefix, use 3. If they are installed in separate locations, use 1. or 2.: if the given library has a common prefix for includes and libs, use 1., otherwise use 2.

Developer Documentation

Please follow the C++ Style Guide when developing.

The design decisions are documented in Design.