Functional Features

Python support

Python integration

Overview of important variables and methods for a correct initialization and usage of Python throughout the project. For a smooth integration, Python needs to be initialized before executing Python code by

// Initialization
#ifdef PYTHON_BACKEND
mcmc::execution::initialize_python(PYTHON_SCRIPTS_PATH);
#endif

and at the end finalized by

// Finalization
#ifdef PYTHON_BACKEND
mcmc::execution::finalize_python();
#endif

The CMake variable RUN_WITH_PYTHON_BACKEND needs to be set by -DRUN_WITH_PYTHON_BACKEND=ON (default=ON) when the library is built.

The optional CMake variable PYTHON_SCRIPTS_PATH can be set by -DPYTHON_SCRIPTS_PATH=<path_to_python_modules> when the project is built. The <path_to_python_modules> refers to the directory containing a custom_modules.pyfile and allowing for an integration of custom measure functions and a custom function for loading MCMC simulation data from file.

static bool mcmc::util::python_integration::g_is_python_initialized: Variable for checking if Python has been initialized correctly.

void mcmc::util::initialize_python(const std::string &python_modules_path, const bool fma_develop = false, const bool executing_from_python = false)

Initialize Python and set important variables.

Parameters

python_modules_path – Path to a directory containing custom Python code
fma_develop – Indicate whether plots should be written to file or loaded Device::locally
executing_from_python – Variable for indicating whether the code is executed from C++ (false) or executed via pybind from Python (true)

void mcmc::util::finalize_python(): Finalize Python.

Integrating external Python modules

static std::string mcmc::util::python_integration::g_python_modules_path: Path to the directory containing the custom_modules.py file with custom Python code for computing measures and loading MCMC simulation data.

static std::string mcmc::util::python_integration::get_python_modules_path(): Returns the g_python_modules_path.

static void mcmc::util::python_integration::set_python_modules_path(const std::string &python_modules_path): Sets the g_python_modules_path.

Utils

Random number generation

Definition of the random generator used throughout the entire project and further useful functions.

static std::random_device mcmc::util::random::g_rd: Random device engine, usually based on /dev/random on UNIX-like systems.

static std::mt19937 mcmc::util::random::g_gen: Mersenne Twister pseudo-random generator used throughout the entire project.

static void mcmc::util::random::set_random_seed(uint32_t seed_val = 0)

Sets the random seed for mcmc::util::random::g_gen used throughout the entire project.

Parameters: seed_val – Random seed
Returns: None

Linspace intervals

template<typename T> std::vector<T> mcmc::util::linspace(T min, T max, uint num = 1)

Returns evenly spaced numbers over a specified interval, where min and max are included.

Parameters

min – Lower bound of the interval
max – Upper bound of the interval
num – Number of numbers in the interval

Returns

A vector with evenly spaced numbers over the specified interval.

Sign function

template<typename T> T mcmc::util::sign(const T value)

Sign function.

Parameters: value – Value
Returns: 1 if value > 0 and -1 if value <= 0.