Using the REnvironment

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Revision as of 07:41, 5 September 2008 by Keilwagen (talk | contribs)
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REnvironment e = null;
try {
	//create a connection to R with YOUR server name, login and password
	e = new REnvironment( server, login, password );

	System.out.println( "java: " + System.getProperty( "java.version" ) );
	System.out.println();
	System.out.println( e.getVersionInformation() );

	// compute something in R
	REXP erg = e.eval( "sin(10)" );
	System.out.println( erg.asDouble() );

	//create a histrgram in R in 3 steps
	//1) create the data
	e.voidEval( "a = 100;" );
	e.voidEval( "n = rnorm(a)" );
	//2) create the plot command
	String plotCmd = "hist(n,breaks=a/5)";
	//3a) plot as pdf
	e.plotToPDF( plotCmd, "./../test.pdf", true );
	//or
	//3b) create an image and show it
	BufferedImage i = e.plot( plotCmd, 640, 480 );
	REnvironment.showImage( "histogramm", i, JFrame.EXIT_ON_CLOSE );

} catch ( Exception ex ) {
	ex.printStackTrace();
} finally {
	if( e != null ) {
		try {
			//close REnvironment correctly
			e.close();
		} catch ( Exception e1 ) {
			System.err.println( "could not close REnvironment." );
			e1.printStackTrace();
		}
	}
}