Formal Concept Analysis

This repository contains a small implementation of an algorithm to analyse a dataset and construct a concept lattice using an algorithm described in Introduction to Lattices and Order by Davey and Priestley (Chapter 3: Formal Concept Analysis).

Installation

This package is written in Haskell and can be compiled using the normal Haskell tools:

cabal configure
cabal build
cabal test
cabal haddock --executables
cabal install

It provides both an executable for use at the command-line and a library. While it exports all the core functionality, the library is unlikely to be of use in other code.

Usage

The package includes a library which implements and exports almost all functionality and an executable, called fca, which provides a command-line interface.

fca - formal concept analysis

Usage: fca [-f|--format ea|eav|tab] [-o|--output FILE] [FILE]
  Generate the concept lattice which describs a data set.

Available options:
  -h,--help                Show this help text
  -f,--format ea|eav|tab   Input data format. (default: EAV)
  -o,--output FILE         Write output to FILE. (default: stdout)
  FILE                     Read input from FILE. (default: stdin)

Input data must be supplied in one of three similar CSV formats:

• entity-attribute format consists of two columns: an object name and an attribute name.

• entity-attribute-value format consists of three columns: an object name, an attribute name, and an attribute value. The attribute name and value will be concatenated to form an attribute suitable for processing.

• tabular format consists of a matrix with objects as rows and attributes as columns; the header row and column contain the names, and a non-empty cell represents the presence of an attribute at an object.

Two examples data sets, each in all three formats, can be found in the data/ directory:

• The .txt file contains a summary of the data;

• The .tab file contains the tabular format;

• The .ea file contains the entity-attribute format; and

• The .eav file contains the entity-attribute-value format.

In all three cases, the object and attribute names have been abbreviated and, when processed, result in the same output.

The output is a graph of the concept lattice in Graphviz format.