title: Algorithm for nice log labels
body: <p>I'm drawing a chart with logarithmic scale that I can zoom and pan.  In the process of zooming and panning I need to be prepared for drawing nice tick labels.  My general problem is: given two points, <code>x0</code> and <code>x1</code>, create a subdivision of <code>n</code> elements in log scale that 'looks nice'.  I have gone through the math gems algorithms about nice grid line but it doesn't work that well for logarithmic scale.  Any pointers?</p>