UseInJulia

How to use the toolkit in Julia

Introduction

The Java code from this toolkit can easily be used in Julia.

Here we give only a brief overview of calling Java code from Julia; several longer examples of using the JIDT toolkit in Julia can be viewed at JuliaExamples.

Using Java objects in Julia

First, you need to install the JavaCall package in Julia; this is done inside a Julia session by calling: Pkg.add("JavaCall").

You can then run your Java code in Julia as follows:

1. Include the JavaCall package with command: using JavaCall;
2. Initialise the JavaCall package and tell it where our infodynamics.jar file is, e.g.: JavaCall.init(["-Djava.class.path=$(jarLocation)"]("-Xmx128M",));
3. Import the classes you wish to use, e.g. teClass = @jimport infodynamics.measures.discrete.TransferEntropyCalculatorDiscrete;.
4. Create an instance of the calculator you wish to use, e.g. teCalc = teClass((jint,jint,), 2, 1)
5. Call methods on the object, passing in the return type of the method and a tuple of argument types and the arguments themselves, e.g. or jcall(teCalc, "getPastCount", int,(int,)), or jcall(teCalc, "initialise", Void,()) for a void return type and no arguments. See how to specify array types below.

Array conversion -- single dimensional arrays can be passed directly back and forth. Take care to indicate their type correctly when passing into a Java method (see JavaCall docs), e.g. jcall(teCalc, "addObservations", Void, (Array{jint,1}, Array{jint,1}), sourceArray, destArray);. Multi-dimensional arrays however are not yet supported in JavaCall (see here). We're looking into whether we can make a conversion script to do this manually ...