gsp_pattern_miner — Logtalk 3.100.1

# `gsp_pattern_miner`

GSP sequential pattern miner for sequence datasets. The library depends on the `sequential_pattern_mining_protocols` support library, implements the generic `pattern_miner_protocol` defined in the `pattern_mining_protocols` core library, and mines frequent sequential patterns using prefix-indexed candidate joins, pruning candidates whose immediate subpatterns are not all frequent, and counting singleton and candidate supports in batched horizontal dataset scans.

Requires a dataset implementing `sequence_dataset_protocol` with sequences represented as ordered lists of canonical sorted itemsets over a declared item domain.

## API documentation

Open the ../../apis/library_index.html#gsp_pattern_miner link in a web browser.

## Loading

To load this library, load the `loader.lgt` file:

    | ?- logtalk_load(gsp_pattern_miner(loader)).

## Testing

To test this library predicates, load the `tester.lgt` file:

    | ?- logtalk_load(gsp_pattern_miner(tester)).

## Features

- Level-Wise Mining: Builds longer frequent sequences by extending the current frequent level.

- Join-Based Candidates: Generates candidate sequences by joining compatible frequent patterns from the previous level.

- Support-Pruned Candidates: Prunes candidates whose immediate subpatterns are not all frequent.

- Batched Horizontal Support Counting: Counts singleton and candidate supports using horizontal scans over the sequence database at each level.

- Canonical Sequences: Validates that itemsets are sorted, duplicate-free, non-empty, and restricted to declared items.

- Flexible Support Thresholds: Supports relative minimum support and absolute minimum support count.

- Model Export: Mined pattern collections can be exported as predicate clauses or written to a file.

## Options

The `mine/3` predicate accepts the following options:

- `minimum_support/1`: Relative minimum support threshold in the interval `]0.0, 1.0]`. The default is `0.5`.

- `minimum_support_count/1`: Absolute minimum support count. When both support options are provided, this option takes precedence.

- `maximum_pattern_length/1`: Maximum total number of items in a mined sequential pattern. The default is `1000`, effectively capped by the longest sequence in the dataset.

- `minimum_pattern_length/1`: Minimum total number of items retained in the mined result. The default is `1`.

## Pattern miner representation

The mined pattern miner result is represented by a compound term with the functor chosen by the implementation and arity 3. For example:

    gsp_pattern_miner(ItemDomain, Patterns, Options)

Where:

- `ItemDomain`: Canonical sorted list of declared dataset items.

- `Patterns`: List of `sequence_pattern(Pattern, SupportCount)` terms ordered first by total item count and then lexicographically.

- `Options`: Effective mining options used to mine the frequent sequential patterns.

## References

1. Srikant, R. and Agrawal, R. (1996) - “Mining sequential patterns: Generalizations and performance improvements”.