Logarithmic Graphs in Graphmatica

[Ascetic Anchorite]

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.

 

[VietDao29]

You might want to use Graph. It's so far one of the 2D sketching programmes that I like best. It's free, and very handy. Just try it and you'll see.
To use logarithmic scale in Graph, you can adjust the axes settings by going to Edit -> Axes, or click on the Edit axes settings icon (the one that shows 2 dotted, blue axes) in the taskbar, or simply use the combination Ctrl-A. A window will pop up. In y-axis tab, tick the Logarithmic scale checkbox. Set the minimum to 0.1, and maximum to 819.2, as you desire. Then uncheck the Auto tick checkbox, then set the Tick unit to 2. And everything is done. :)
Is this what you want? :)

 

[Ascetic Anchorite]

Thanks very much. I will give it a try.