fcars

fcars stands for Formal Concept Analysis in Rust.

fcars is both a binary for computing formal concepts from the command line and a library for arbitrary FCA computations.

Usage

Binary

To install the fcars binary on your system, you need to have cargo installed. Then run:

> cargo install fcars

The basic command-line interface is:

> fcars [-n] [-V] [-o file_out] [--dat | --cxt] [file_in]

Use -n to print only the number of concepts, -V to print the context before computing concepts, and -o to write output to a file instead of stdout. If no input file is given, fcars reads from stdin. fcars -h displays full usage info.

Example Binary Usage

A classic example in Formal Concept Analysis is the "Lives in Water" context. Using the .cxt file provided here by Uta Priss, we can have fcars enumerate its concepts:

> fcars --cxt lives_in_water.cxt

Expected Output

Extent: ["fish leech", "bream", "frog", "dog", "water weeds", "reed", "bean", "corn"], Intent: ["needs water to live"]
Extent: ["fish leech", "bream", "frog", "water weeds", "reed"], Intent: ["needs water to live", "lives in water"]
Extent: ["frog", "dog", "reed", "bean", "corn"], Intent: ["needs water to live", "lives on land"]
Extent: ["water weeds", "reed", "bean", "corn"], Intent: ["needs water to live", "needs chlorophyll"]
Extent: ["fish leech", "bream", "frog", "dog"], Intent: ["needs water to live", "can move"]
Extent: ["frog", "reed"], Intent: ["needs water to live", "lives in water", "lives on land"]
Extent: ["water weeds", "reed"], Intent: ["needs water to live", "lives in water", "needs chlorophyll", "monocotyledon"]
Extent: ["fish leech", "bream", "frog"], Intent: ["needs water to live", "lives in water", "can move"]
Extent: ["reed", "bean", "corn"], Intent: ["needs water to live", "lives on land", "needs chlorophyll"]
Extent: ["frog", "dog"], Intent: ["needs water to live", "lives on land", "can move", "has limbs"]
Extent: ["water weeds", "reed", "corn"], Intent: ["needs water to live", "needs chlorophyll", "monocotyledon"]
Extent: ["bream", "frog", "dog"], Intent: ["needs water to live", "can move", "has limbs"]
Extent: ["reed"], Intent: ["needs water to live", "lives in water", "lives on land", "needs chlorophyll", "monocotyledon"]
Extent: ["frog"], Intent: ["needs water to live", "lives in water", "lives on land", "can move", "has limbs"]
Extent: ["bream", "frog"], Intent: ["needs water to live", "lives in water", "can move", "has limbs"]
Extent: ["bean"], Intent: ["needs water to live", "lives on land", "needs chlorophyll", "dicotyledon"]
Extent: ["reed", "corn"], Intent: ["needs water to live", "lives on land", "needs chlorophyll", "monocotyledon"]
Extent: ["dog"], Intent: ["needs water to live", "lives on land", "can move", "has limbs", "breast feeds"]
Extent: [], Intent: ["needs water to live", "lives in water", "lives on land", "needs chlorophyll", "dicotyledon", "monocotyledon", "can move", "has limbs", "breast feeds"]

Library

To use the fcars library, add

fcars = "0.2.2"

to the [dependencies] section of your Cargo.toml file.

Or, to also enable generating random formal contexts, use

fcars = {version = "0.2.2", features = ["random"]}

Example Library Usage

With the "random" feature enabled, you can write:

use fcars::*;

fn main() {
    let context = FormalContext::random_with_density(10, 12, 0.8);
    println!("Context:\n{}", context);
    let concepts = context.all_concepts();
    println!("Reduced? {}\n", context.is_reduced());
    for concept in concepts {
        println!("{}", concept);
    }
}