On May 14, 7:41 am, Ant <ant...@gmail.com> wrote: > Hi All, > > I am trying to get matplotlib to overlay a couple of graphs, but am > getting nowhere. I originally thought that the following may work: > > >>> x = [1,2,3,4,5] > >>> y = [2,4,6,8,10] > >>> y2 = [1,4,9,16,25] > >>> plot(x, y) > >>> plot(x, y2) > > Now this works as desired, however, the actual case I have is more > like this: > > >>> x = [1,2,3,4,5] > >>> y = [2,4,6,8,10] > >>> y2 = [.0001, .0002, .0003, .0004, .0005] > > Now the graph is useless, since the results are plotted on the same > axis. What I really want is two different sets of axes, each scaled > appropriately, but overlayed. > > The data I actually have, is one set of axes plotting distance against > elevation, and a second plotting distance against speed. The former > has (y-coord) units in the range 0-2000 ft and the latter 0 - 0.01 > miles/second. I want them on the same graph, so points can be easily > correlated, but overlayed so that each line has a different scale on > the y-axis. The closest I can get is to have two subplots, one above > the other. > > Thanks in advance, > > Ant.
Just scale up the y-axis values of your second graph 200,000 times, and specify in label that the y-axis for the second graph is velocity scaled up 200000x for comparison purposes. Nothing wrong with that-- it's done all the time. On the other hand, I just took a peek at the matplotlib example gallery, which is very diverse, and it has an example that I think is exactly what you're looking for: http://matplotlib.sourceforge.net/examples/api/two_scales.html -- http://mail.python.org/mailman/listinfo/python-list
