I've got a routine, attached, which is simple and fast, and returns very nicely spaced ticks along with the number of minor ticks. It's an old algorithm from a '73 ACM article, but tried and true. I suppose this should be implemented as a Locator, but I'm not very familiar with the pylab code. Perhaps someone could demonstrate the appropriate way? -- Tom Holroyd, Ph.D. We experience the world not as it is, but as we expect it to be.