public Printer(NetworkGraph graph, boolean graphic) {
		if (graphic) {
			jc = new JCanvas();
			jc.setPreferredSize(new Dimension(700,800));
			jc.addDrawable(graph);
			GUIHelper.showOnFrame(jc,"Genetic algorithm");
			lastRefresh = System.currentTimeMillis();
		}
		else 
			jc = null;
	}