ixa-pipe-wikify

This repository contains the Wikification tool based on DBpedia Spotlight. ixa-pipe-wikify is part of IXA pipes, a multilingual NLP pipeline developed by the IXA NLP Group.

Providing that a DBpedia Spotlight Rest server for a given language is running, the ixa-pipe-wikify module takes a NAF document containing wf and term elements as input, performs Wikification for your language of choice, and outputs a NAF document with references to DBpedia on markables element (<markables source="DBpedia_spotlight">)

Module contents

The contents of the module are the following:

+ src/   	    java source code of the module
+ pom.xml 	    maven pom file wich deals with everything related to compilation and execution of the module
+ README.md	    this README file
+ Furthermore, the installation process, as described in the README.md, will generate another directory:
target/	    it contains binary executable and other directories

INSTALLATION

Installing the ixa-pipe-wikify requires the following steps:

If you already have installed in your machine the Java 1.7+ and MAVEN 3, please go to step 3 directly. Otherwise, follow the detailed steps

1. Install JDK 1.7

If you do not install JDK 1.7 in a default location, you will probably need to configure the PATH in .bashrc or .bash_profile:

export JAVA_HOME=/yourpath/local/java17
export PATH=${JAVA_HOME}/bin:${PATH}

If you use tcsh you will need to specify it in your .login as follows:

setenv JAVA_HOME /usr/java/java17
setenv PATH ${JAVA_HOME}/bin:${PATH}

If you re-login into your shell and run the command

java -version

you should now see that your JDK is 1.7.

2. Install MAVEN 3

Download MAVEN 3 from

wget http://ftp.udc.es/apache/maven/maven-3/3.0.4/binaries/apache-maven-3.0.4-bin.tar.gz

Now you need to configure the PATH. For Bash Shell:

export MAVEN_HOME=/yourpath/local/apache-maven-3.0.4
export PATH=${MAVEN_HOME}/bin:${PATH}

For tcsh shell:

setenv MAVEN3_HOME ~/local/apache-maven-3.0.4
setenv PATH ${MAVEN3}/bin:{PATH}

If you re-login into your shell and run the command

mvn -version

You should see reference to the MAVEN version you have just installed plus the JDK 7 that is using.

3. Download and install statistical backend - DBpedia Spotlight

If you already have installed DBpedia Spotlight for ixa-pipe-ned module in your machine, please go to step 4 directly. Otherwise, follow the detailed steps

Download the statistical backend of DBpedia Spotlight:

wget http://spotlight.sztaki.hu/downloads/dbpedia-spotlight-latest.jar

Go to the directory the dbpedia-spotlight-latest.jar is located and execute:

mvn install:install-file -Dfile=dbpedia-spotlight-latest.jar -DgroupId=ixa -DartifactId=dbpedia-spotlight -Dversion=0.7 -Dpackaging=jar -DgeneratePom=true

This command will install dbpedia-spotlight jar as a local maven repository.

4. Download and update the language models

If you already use DBpedia Spotlight for ixa-pipe-ned module in your machine, you only have to change the parameter as described at the end of this step

Download the required language model:

• German model:

wget http://spotlight.sztaki.hu/downloads/latest_models/de.tar.gz

• English model:

wget http://spotlight.sztaki.hu/downloads/latest_models/en.tar.gz

• Spanish model:

wget http://spotlight.sztaki.hu/downloads/latest_models/es.tar.gz

• French model:

wget http://spotlight.sztaki.hu/downloads/latest_models/fr.tar.gz

• Italian model:

wget http://spotlight.sztaki.hu/downloads/latest_models/it.tar.gz

• Dutch model:

wget http://spotlight.sztaki.hu/downloads/latest_models/nl.tar.gz

Untar the language model:

tar xzvf $lang.tar.gz

$lang variable refers to "de" for German, "en" for English, "es" for Spanish, "fr" for French, "it" for Italian and "nl" for Dutch

Change a parameter in the model in order to do wikification: open the $lang/spotter_thresholds.txt file and change the last number to 1.0 (you should have something like this: 1.0 0.2 -0.2 1.0)

5. Start the DBpedia Spotlight server

If you already use DBpedia Spotlight for ixa-pipe-ned module in your machine and the server is running at the moment, you have to stop the server, change the model parameter as described in the previous step and re-start the server as described here

java -jar dbpedia-spotlight-latest.jar $lang http://localhost:$port/rest 

See previous section for $lang variable description.

$port variable takes one of the following values depending on the language:

• de: 2010
• en: 2020
• es: 2030
• fr: 2040
• it: 2050
• nl: 2060

6. Get module source code

git clone https://github.com/ixa-ehu/ixa-pipe-wikify

7. Compile

cd ixa-pipe-wikify
mvn clean package

This step will create a directory called 'target' which contains various directories and files. Most importantly, there you will find the module executable:

ixa-pipe-wikify-${version}.jar

This executable contains every dependency the module needs, so it is completely portable as long as you have a JVM 1.7 installed.

USAGE

The ixa-pipe-wikify requires a NAF document (with wf and term elements) as standard input and outputs NAF through standard output. You can get the necessary input for ixa-pipe-wikify by piping ixa-pipe-tok and ixa-pipe-pos as shown in the example below.

It also requires the port number as argument. The port numbers assigned to each language are the following:

• de: 2010
• en: 2020
• es: 2030
• fr: 2040
• it: 2050
• nl: 2060

Once you have a DBpedia Spotlight Rest server running you can send queries to it via the ixa-pipe-wikify module as follows:

cat text.txt | ixa-pipe-tok | ixa-pipe-pos | java -jar ixa-pipe-wikify-${version}.jar -p $PORT_NUMBER

There are several optional parameters:

• -s: Server. Specify hostname in which dbpedia-spotlight rest server is being executed (default value is 'http://localhost').
• -cor: Boolean value for coreference resolution. When is true, no other filter will be applied (default value is 'false').
• -con: Confidence filter. Selects all entities that have a confidence greater than this double value (default value is '0.0').
• -sup: Support filter. Selects all entities that have a support greater than this integer value (default value is '0').
• -i: Specify the path to the 'database' created by MapDB to find the corresponding English crosslingual link (more details below).
• -n: Specify the name of the HashMap in the index to be used; i.e. 'esEn' for English crosslingual links for Spanish (more details below).

When the language is other than English, the module offers an additional feature. It is possible to set the corresponding English entry also. To use this option, execute the module as follows:

cat text.txt | ixa-pipe-tok | ixa-pipe-pos | java -jar ixa-pipe-wikify-${version}.jar -p $PORT_NUMBER -i $INDEX -n $HASH_NAME

So far, you can download and untar the following package for Spanish crosslingual links:

wget http://ixa2.si.ehu.es/ixa-pipes/models/wikipedia-db.tar.gz
tar xzvf wikipedia-db.tar.gz

And then execute as follows (for Spanish):

cat text.txt | ixa-pipe-tok | ixa-pipe-pos | java -jar ixa-pipe-wikify-${version}.jar -p 2030 -i wikipedia-db -n esEn

For more options running ixa-pipe-wikify:

java -jar ixa-pipe-wikify-${version}.jar -h

Contact information

Arantxa Otegi
arantza.otegi@ehu.es
IXA NLP Group
University of the Basque Country (UPV/EHU)
E-20018 Donostia-San Sebastián