private static Path tempPath() throws IOException {
		return createTempFile("__gnuplot_template__", "__.gp").toPath();
	}
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