R: Find Generator Itemsets

is.generator {arules} | R Documentation

## Find Generator Itemsets

### Description

Provides the generic function and the S4 method `is.generator` for finding generator itemsets. Generators are part of concise representations for frequent itemsets. A generator in a set of itemsets is an itemset that has no subset with the same support (Liu et al, 2008). Note that the empty set is by definition a generator, but it is typicaly not stored in the itemsets in arules.

### Usage

    is.generator(x)

### Arguments

`x` | a set of itemsets.

### Value

a logical vector with the same length as `x` indicating for each element in `x` if it is a generator itemset.

### Author(s)

Michael Hahsler

### References

Yves Bastide, Niolas Pasquier, Rafik Taouil, Gerd Stumme, Lotfi Lakhal (2000). Mining Minimal Non-redundant Association Rules Using Frequent Closed Itemsets. In International Conference on Computational Logic, Lecture Notes in Computer Science (LNCS 1861). pages 972–986. doi: 10.1007/3-540-44957-4_65

Guimei Liu, Jinyan Li, Limsoon Wong (2008). A new concise representation of frequent itemsets using generators and a positive border. Knowledge and Information Systems 17(1):35-56. doi: 10.1007/s10115-007-0111-5

### See Also

`itemsets-class`, `is.closed`, `is.maximal`

### Examples

    # Example from Liu et al (2008)
    trans_list <- list(
          t1 = c("a","b","c"),
          t2 = c("a","b", "c", "d"),
          t3 = c("a","d"),
          t4 = c("a","c")
          )

    trans <- transactions(trans_list)
    its <- apriori(trans, support = 1/4, target = "frequent itemsets")

    is.generator(its)

[Package arules version 1.7-2 Index]