How to use Logarithmic axis using Shinobi Premium chart for iOS?


I am using Shinobi Chart Premium in my project. I have to use the Logarithmic axis to set my y-axis. But I am not able to set the base for the axis. 

The chart values ranges from thousands to milions. What Base value should I have to actually set to get my chart shown properly on the screen?

SChartLogarithmicAxis *yAxis = [[SChartLogarithmicAxisalloc] init];

yAxis.base = [NSNumbernumberWithFloat:10.0];

Any idea what should be done here?