Is it possible to set your own interval on a logarithmic scale?

Jul 12, 2013 at 3:35 PM
I'm trying to create a more natural logarithmic scale, much like the x axis on this graph..

http://openeeg.sourceforge.net/doc/modeeg/images/filter_delay_log.png

By setting the base to 2.718281828 I get this, but the intervals between the major ticks aren't right and the values that have been chosen are pretty random and I need them rounding to more meaningful values.

This is the output at the minute.

https://www.dropbox.com/s/5dr70tk34vz1wp2/logscale.jpg

This is now a real sticking point in using this library in my application which would be a real shame as I've got some brilliant results so far.

If anyone can help me out then I can share some code then.
Jul 12, 2013 at 3:51 PM
Edited Jul 12, 2013 at 4:03 PM
I think I need to be setting the major step but i'm not sure...

So this is exactly what I want...

https://www.dropbox.com/s/njef6lzuts2qrof/log2.png

But this is plotting from 0.1 to 1.

I need to plot from 0(ish) to 32,800.
Jul 12, 2013 at 8:13 PM
Edited Jul 12, 2013 at 8:16 PM
I don't understand completely your question, but at first glance: won't it be enough for you to set the Maximum/Minimum of the axis?

                LogarithmicAxis axis1 = new LogarithmicAxis();
                axis1.Position = AxisPosition.Bottom;
                axis1.Base = 8;
                axis1.MinorStep = 2;
                axis1.MinorGridlineStyle = LineStyle.Dot;
                axis1.MinorGridlineColor = OxyColors.LightGray.ChangeAlpha(20);
                axis1.Minimum = 0;
                axis1.Maximum = 32800;

                plotter.Model.Axes[0] = axis1;
                plotter.RefreshPlot(true);
Results:

Log2
Image

Log8
Image

Log10
Image



I think you can't retrieve the label for minor ticks right now, correct if I'm wrong.

By the way: why would you set the base to "e"? Its logical to obtain "random" values (e^2, e^3...)