ElkCommandLine

Using ELK from the Command Line

ELK can be invoked via a simple command line interface that is provided by the ELK standalone package.

Installation

To use the command line client, it suffices to download and unzip the most recent version of elk-standalone from the Getting ELK page.

Running the Command-Line Client

You can invoke the client with the following command:

java -jar elk-standalone.jar

provided that you are in the directory where the jar file is found. Otherwise, the full or relative path to the file must be used (syntax depending on your operating system). You may want to specify further Java parameters for increasing available memory for classifying larger ontologies, e.g. by setting

java -XX:+AggressiveHeap -jar elk-standalone.jar

or by providing a increased maximum heap size such as -Xmx3000m.

Parameters for Controlling the Client

Invoking the ELK Client without further parameters displays a list of supported options. A typical example call is as follows:

java -jar elk-standalone.jar -i ontology.owl --classify -o taxonomy.owl

This will load the ontology from the file ontology.owl, compute its classification and store the result in the file taxonomy.owl. Without the output parameter ELK will still compute the result but it will neither store nor display the result anywhere; this can be used for performance experiments.

If ELK cannot parse your ontology, this is probably because it is in the RDF/XML syntax. The command line client can only read ontologies in OWL 2 Functional-Style Syntax. OWL ontologies in other formats can be converted into Functional-Style Syntax using Protégé version 4.1 or higher. To convert a file, open it in Protege and save using the menu:

File > Save as... > OWL Functional Syntax.

Alternatively, you can also use the EKL Protégé plugin directly.