Sympy and ExprTk¶

SLOTH provides interfaces with the C++ Mathematical Expression Toolkit Library ExprTk and the Python library for symbolic mathematics Sympy to handle physical properties with Coefficient.

Installing Sympy

Sympy is a mandatory prerequisite to build SLOTH. Please ensure that Sympy is well installed.

This page presents the instructions for installing these dependencies.

ExprTk¶

The following installation procedure describes how to install and link the library ExprTk to SLOTH applications.

Getting ExprTk¶

The C++ Mathematical Expression Toolkit Library ExprTk is contained in the C++ file name exprtk.hpp which can be downloaded either from the ExprTk website or with spack by running the following instructions in a terminal:

spack install exprtk

Other approaches exist as, for example, the use of conda.

Linking SLOTH and ExprTk¶

To link SLOTH with ExprTk, the user must run the envSloth.sh script file with the --exprtk option:

bash ../envSloth.sh [OPTIONS] --exprtk=$EXPRTK_PATH

where EXPRTK_PATH is an environment variable setting the path toward the exprtk folder containing the file exprtk.hpp and [OPTIONS] are:

    --release        Build with Release compiler options

    --optim          Build with Optim compiler options

    --debug          Build with Debug compiler options

    --coverage       Build with Coverage compiler options

    --minsizerel     Build with MinSizeRel compiler options

    --relwithdebinfo Build with RelWithDebInfo compiler options

    --external       Build SLOTH with an external package

    --shared         Build a shared library for Sloth

    --install        Specify the installation path for Sloth 
                     (default: a "SlothInstallation" directory at the same level as the repository)

    --np             Specify the number of CPUs to use for compilation (default: 4)

With spack, this environment variable can be defined as:

export EXPRTK_PATH=$(spack location -i exprtk)/include/exprtk

Sympy¶

The Python script GenerateCoefficient.py (see the script folder in the SLOTH repository) used to build coefficients from a mathematical expression is built on top of Sympy.

To install Sympy and use the Python script GenerateCoefficient.py, the following instruction can be run in a terminal:

pip install Sympy

Users are free to use other installation procedures as described in the Sympy website.