This repository contains library for inflection of Czech nouns, which is available under the CC BY-NC-SA 4.0 license. The work is described in the following paper:
The paper by Tomáš Sourada, Jana Straková, Rudolf Rosa, accepted to LREC-COLING 2024: OOVs in the Spotlight: How to Inflect them?
Czech OOV Inflection Dataset, introduced in the paper, stored at LINDAT repository, aiming at rigorous evaluation of inflection in out-of-vocabulary conditions.
Development repository for the project with all additional data and script.
A bachelor thesis Automatic inflection in Czech language describes the work more profoundly, including all theoretical and technical details.
You can find the material presenting the project in the presentations directory:
This project provides a morphological guesser for inflection of Czech nouns. It focuses on inflection of out-of-vocabulary words. (For other words we recommend MorphoDiTa tool https://lindat.mff.cuni.cz/services/morphodita/ )
The guesser is a LSTM-based encoder-decoder architecture with attention, trained with OpenNMT-py library on a training dataset consisting of approx. 360k Czech noun lemmata (data source: MorfFlex2.0 https://lindat.mff.cuni.cz/repository/xmlui/handle/11234/1-3186 ).
To build the project requirements, run
bash build.sh
You will need approx. 5GB disk space for installing the requirements.
To run the inflection script after building the requirements, run
bash run.sh
Install python3 dependencies from file requirements.txt to you environment (ideally virtualenv). Run the inflect.py script from the environment.
To exit the running program, press Ctrl+D.
The inflection script reads stdin line by line. It expects one lemma (Czech noun in base form) per line. It prints the tab-separated inflected forms to stdout. The number of produced forms is 14 and they are printed in the following order: S1 S2 S3 S4 S5 S6 S7 P1 P2 P3 P4 P5 P6 P7
(S=singular, P=plural, 1..7 are cases numbered as usual in Czech morphology: 1=nominative, ..., 7=instrumental)
Example input: jablko
Example output: jablko jablka jablku jablko jablko jablku jablkem jablka jablek jablkům jablka jablka jablkách jablky
Example input: pes
Example output (incorrect prediction): pes pesu psi pes pese psi psem psi psů psům pse psi pesech psi
Inflection of the first lemma takes relatively long time (~10s) due to loading the inflection model, other lemmata are inflected more quickly.
The inflection system is case-sensitive. It is not able to inflect phrases (it automatically deletes spaces in the input sequence). It is not capable of inflecting words containing almost any of special characters ('-', '_', ...), and it substitutes such characters by a character from its vocabulary.