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Pack logtalk -- logtalk-3.100.1/docs/handbook/_sources/libraries/clo_span_pattern_miner.rst.txt

.. _library_clo_span_pattern_miner:

clo_span_pattern_miner

CloSpan closed 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 closed frequent sequential patterns directly using closure-aware projected-database search with explicit projected-database-equivalence backward pruning that skips equivalent branches before recursion, together with a same-support closed frontier that merges branch results during the search without a final post-filter.

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#clo_span_pattern_miner <../../apis/library_index.html#clo_span_pattern_miner>`__ link in a web browser.

Loading

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

::

| ?- logtalk_load(clo_span_pattern_miner(loader)).

Testing

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

::

| ?- logtalk_load(clo_span_pattern_miner(tester)).

Features

  • Closed Pattern Mining: Retains only frequent sequential patterns that have no superpattern with the same support.
  • Backward and Closure Pruning: Uses projected-database equivalence to skip equivalent backward-growth branches before recursion, then maintains a same-support closed frontier to suppress dominated patterns during the search instead of post-filtering another miner output.
  • Canonical Sequences: Uses the shared sequential validation logic from the support library.
  • Flexible Support Thresholds: Supports relative minimum support and absolute minimum support count. When both are given, the absolute-count threshold takes precedence.
  • Model Export: Closed 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:

::

clo_span_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 closed sequential patterns.

References

  1. Yan, X., Han, J., and Afshar, R. (2003) - "CloSpan: Mining closed sequential patterns in large datasets".