Backend: STWFSA

The STWFSA backend is a wrapper around STWFSAPY, a lexical algorithm based on finite state automata.

It is best suited for English language data.

Installation

See Optional features and dependencies.

Example configuration

A minimal configuration:

[yso-stwfsa-en]
name=STWFSA YSO english
language=en
backend=stwfsa
vocab=yso

A configuration using custom classes for concept types, sub-thesauri and their relations (see parameter documentation below for more information).

[stw-stwfsa-en]
name=STWFSA STW english
language=en
backend=stwfsa
vocab=stw
concept_type_uri=http://zbw.eu/namespaces/zbw-extensions/Descriptor
sub_thesaurus_type_uri=http://zbw.eu/namespaces/zbw-extensions/Thsys
thesaurus_relation_type_uri=http://www.w3.org/2004/02/skos/core#broader
thesaurus_relation_is_specialisation=False

Backend-specific parameters

The parameters are:

Parameter	Description
concept_type_uri	The type of the concepts in your graph, defaults to http://www.w3.org/2004/02/skos/core#Concept.
sub_thesaurus_type_uri	Optional type for sub-thesaurus structure in your vocabulary, defaults to http://www.w3.org/2004/02/skos/core#Collection.
thesaurus_relation_type_uri	Optional type of relation between concepts and sub-thesaurus entries. Defaults to http://www.w3.org/2004/02/skos/core#member
thesaurus_relation_is_specialisation	Set to false if thesaurus_relation_type_uri is a specialisation relation instead of a generalisation relation. I.e., if you have (concept, thesaurus_relation_type_uri, sub-thesaurus) triples in your graph it should be set to False. Conversely it should be set to True if you have (sub-thesaurus, thesaurus_relation_type_uri, concept) in your graph. Defaults to True.
remove_deprecated	Whether to remove deprecated concepts, enabled by default.
handle_title_case	Disable to not match title case versions of concept labels, disabled by default.
extract_upper_case_from_braces	Removes the explanation in braces from labels. I.e., GDP (Gross Domestic Product) will be transformed to GDP
extract_any_case_from_braces	Can extract content of braces in labels. I.e., R&D (research and discovery) will be transformed to research and discovery. In contrast to extract_upper_case_from_braces it will extract the part inside the parenthesis and not the part before. Disabled by default.
expand_ampersand_with_spaces	For labels that contain an ampersand it will also match text containing spaces around that symbol. I.e., R & D will be matched for label R&D. Enabled by default.
expand_abbreviation_with_punctuation	For labels containing only uppercase letters it will also match text with punctuation added. I.e., G.D.P. for label GDP. Enabled by default.
simple_english_plural_rules	Can detect simple English plural forms of labels. Disabled by default.

If your vocabulary has a hierarchical structure you can use the parameters sub_thesaurus_type_uri, thesaurus_relation_type_uri and thesaurus_relation_is_specialisation. This will help the algorithm detect structure in the vocabulary that it can exploit.

Usage

Load a vocabulary:

annif load-vocab yso /path/to/Annif-corpora/vocab/yso-skos.ttl

Train the model:

annif train yso-stwfsa-en /path/to/Annif-corpora/training/yso-finna-en.tsv.gz

Test the model with a single document:

cat document.txt | annif suggest yso-stwfsa-en

Evaluate a directory full of files in fulltext document corpus format:

annif eval yso-stwfsa-en /path/to/documents/

Provenance / contact information

STWFSAPY has been developed as part of the automatization effort for subject indexing (AutoSE) at ZBW – Leibniz Information Centre for Economics (Hamburg/Kiel, Germany).

If you have questions about the algorithm or about AutoSE in general, please use the contact information given on the AutoSE webpage.