fixed the logit business (we weren't computing logits for the apdps, just the actual values).
Added an example to the 'example' section of the code.
Added documentation for the plot_pdp option.
changed argument pct_to_plot -> frac_to_plot for consistency.
Changed argument name to "frac_to_plot" for consistency.
Changed 'plot_log' argument name to 'logodds'. There is no plotting in the amdp function.
changed argument name to logodds from plot_log
changed argument name to frac_to_plot
changed argument name