How can I create a single graph with two Y axes; e.g. axis y1 on the left side and axis y2 on the right side? I do not mean splitting the y axis which separately displays different ranges of y as two plots one above the other. I need to display one y axis with range 0 to 1.0 and the other with range 1E6 to 1E9 so that two curves are displayed together. They have a common X axis.