I am trying to scale the y-axis as follows: 0.1 0.4 0.8 1.6 3.2 6.4 12.8 25.6 51.2 102.4 204.8 406.9 819.2 I want the major units to double with each step up the y-axis, starting at 0.1 and terminating at 819.2. The problem is, I have no idea how to achieve this! I tried using the logarithmic option in Excel, and also in OpenOffice Calc, but it was of little help and did not seem to allow me the flexibility I need. The logarithmic option in Calc scaled the graph 0.1, 1, 10, 100, 1000. This does not provide enough resolution. I was told Graphmatica ( http://www8.pair.com/ksoft/ ) will allow me to achieve my goal. But I have no idea how to use Graphmatica and there seem to be no tutorials for it anywhere? I do not even know where in Graphmatica i am supposed to enter the equations? This is the formulae I would like to illustrate on a graph: Tan(90-As)*1.205*pi*2 And also (on the same chart): 1.205/cos(90-As)*pi*2 Where: As = Steering angle (0 to 90 degrees). My intention is to illustrate the difference in turning circles between the rear wheel and the front wheel for a bicycle with a wheelbase of 1.205 meters. Any help appreciated.