private static String toParamString(final Map.Entry<String, String> entry) {
		return format("%s='%s'", entry.getKey(), entry.getValue());
	}
Generate the Gnuplot graph.

@param data the input data file
@param output the output path of the graph
@throws IOException if the Gnuplot generation fails
jenetics.tool/src/main/java/io/jenetics/tool/trial/Gnuplot.java