# CorrelationFunctions.jl

This package is a collection of correlation functions described in Salvatore Torquato's book "Random Heterogeneous Materials" ISBN 978-1-4757-6357-7. These functions can be calculated for one-, two- or three-dimensional multiphase systems using closed walls (CW) or periodic boundary conditions (PBC) along multiple directions.

Correlation functions can be calculated using two slightly different ways. The first way is to calculate them across several predefined directions (e.g. axial directions of an array). Another way is to build a correlation map, in other words to calculate a correlation function in all possible directions in a given array. The first way is implemented in `CorrelationFunctions.Directional`

module and the second is implemented in `CorrelationFunctions.Map`

module.

Here is a documentation for each of those modules and some helper functions.

**Directional Functions**. Correlation functions across predefined directions.**Correlation Maps**. Correlation maps or correlation functions in all directions.**Utilities**. Utility functions.**Higher order statistics**. Three-point correlation functions.