C-Apriori

A fast C implementation of the Apriori algorithm

About the project

This repository contains a reasonably fast implementation for the apriori algorithm.

Getting Started

To get a local copy up and running follow these simple steps.

Prerequisites

You need to the following to be able to compile and run the project

• Make

Setup

To set up the program, run the following commands:

    git clone git@github.com:BugelNiels/c-apriori.git
    make

Running

You can run the project as follows with a given data file myDataFile.csv as follows:

./apriori myDataFile.csv

Running it without any additional arguments will assume a minimum support of 0.005 and a minimum confidence of 0.6. Alternatively, you can provide the minimum support and confidence via tha commandline arguments:

./apriori myDataFile.csv 0.005 0.6

Input data file

The CSV file represents contains the information of the products and the transactions. Every row represents a transaction. A cell in the csv has the value t if the product specified in the column occured in said transaction. A simply csv file might look like this:

A,B,C,D,E
t,,t,t,
,t,t,,t
t,t,t,,t
,t,,,t

Running the apriori algorithm on this CSV with a minimum support of 0.5 and a minimum confidence of 0.75:

./apriori simple.csv 0.5 0.75

Produces the following output containing the association rules:

Size of large itemsets l(1) 4
Size of large itemsets l(2) 4
Size of large itemsets l(3) 1

{C, E}                                                        => {B}                            Confidence: 100.0
{B, C}                                                        => {E}                            Confidence: 100.0
{A}                                                           => {C}                            Confidence: 100.0
{E}                                                           => {B}                            Confidence: 100.0
{B}                                                           => {E}                            Confidence: 100.0

Execution took 0.000306 sec.

For myDataFile.csv, the following output is produced:

No minimum support and confidence provided; using defaults 0.005 and 0.6

Size of large itemsets l(1) 120
Size of large itemsets l(2) 628
Size of large itemsets l(3) 279
Size of large itemsets l(4) 14

{citrus_fruit, root_vegetables, whole_milk}                   => {other_vegetables}             Confidence: 63.3
{fruit_vegetable_juice, other_vegetables, yogurt}             => {whole_milk}                   Confidence: 61.7
{pip_fruit, root_vegetables, whole_milk}                      => {other_vegetables}             Confidence: 61.4
{other_vegetables, pip_fruit, root_vegetables}                => {whole_milk}                   Confidence: 67.5
{other_vegetables, pip_fruit, yogurt}                         => {whole_milk}                   Confidence: 62.5
{root_vegetables, tropical_fruit, yogurt}                     => {other_vegetables}             Confidence: 61.2
{other_vegetables, root_vegetables, whipped_sour_cream}       => {whole_milk}                   Confidence: 60.7
{other_vegetables, root_vegetables, yogurt}                   => {whole_milk}                   Confidence: 60.6
{other_vegetables, tropical_fruit, yogurt}                    => {whole_milk}                   Confidence: 62.0
{root_vegetables, tropical_fruit, yogurt}                     => {whole_milk}                   Confidence: 70.0
{bottled_water, butter}                                       => {whole_milk}                   Confidence: 60.2
{butter, domestic_eggs}                                       => {whole_milk}                   Confidence: 62.1
{butter, root_vegetables}                                     => {whole_milk}                   Confidence: 63.8
{butter, tropical_fruit}                                      => {whole_milk}                   Confidence: 62.2
{butter, whipped_sour_cream}                                  => {whole_milk}                   Confidence: 66.0
{butter, yogurt}                                              => {whole_milk}                   Confidence: 63.9
{curd, tropical_fruit}                                        => {whole_milk}                   Confidence: 63.4
{domestic_eggs, margarine}                                    => {whole_milk}                   Confidence: 62.2
{domestic_eggs, pip_fruit}                                    => {whole_milk}                   Confidence: 62.4
{domestic_eggs, tropical_fruit}                               => {whole_milk}                   Confidence: 60.7
{onions, root_vegetables}                                     => {other_vegetables}             Confidence: 60.2
{pip_fruit, whipped_sour_cream}                               => {other_vegetables}             Confidence: 60.4
{pip_fruit, whipped_sour_cream}                               => {whole_milk}                   Confidence: 64.8

Execution took 0.558534 sec.