public void writePresentAbsenceDataForR( File file) throws Exception
	{
		BufferedWriter writer = new BufferedWriter(new FileWriter(file));
		
		for( int x=0; x < getSampleNames().size(); x++)
			writer.write( getSampleNames().get(x) + (x < getSampleNames().size()-1 ? "\t" : "\n") );
		
		for( int y=0; y < getOtuNames().size(); y++)
		{
			for( int x=0; x < getSampleNames().size(); x++)
				writer.write( 
						(getDataPointsUnnormalized().get(x).get(y) > 0.1 ? "1" : "0") + 
						 (x < getSampleNames().size()-1 ? "\t" : "\n") );	
		}
		
		writer.flush();  writer.close();
	}