[R] REngine hangs when called within java code

[aruni karunarathne]

Dear All,

I'm creating a project which uses both java and R.

I created the java class named MyClass and within that wrote two
separate methods (graphing1() and fitness()) to call the r scripts.

public void graphing1() throws IOException {

    String newargs1[] = {"--no-save"};

    Rengine r1 = new Rengine(newargs1, false, null);

    r1.eval("source('test2.R')");

    r1.end();

}



public void fitness() throws IOException {

    String newargs1[] = {"--no-save"};

    Rengine r3 = new Rengine(newargs1, false, null);

    r3.eval("source('A.R')");

    r3.eval("source('B.R')");

    r3.end();

}

Both of the above methods are in java class MyClass.

>From another class in the same project for which I created a gui, I
accessed the fitness() function and it worked fine. But when I try to
call the graphing1() function it did not work. (both were called
through the gui) The programme hangs at ;

Rengine r1 = new Rengine(newargs1, false, null);

without any notification. In both instances I called the function as follows:

1st instance:

MyClass test=new MyClass();

    test.fitness() ;

2nd instance:

MyClass test1 = new MyClass();

        test1.graphing1();



All the 3 scripts are coded to create png files. test2.R and A.R
scripts use the ROCR library and B.R do not use any. All the 3 files
end with dev.off() statement.

I have installed R 3.1.3. I’m using netbeans as the editor and working
in windows environment.

The 3 scripts work fine when executed in R environment. The issue
arises when it’s called from the java code.

I'm a student who is new to R and was struggling to solve this issue
for several weeks. Your help is greatly appreciated.

Thanks in advance.
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