Penalised Maximum Likelihood (PML) method (hmtk)

[Hasib Abdulrazaq]

hi all

I am using the penalised_pml.py script in hmtk folder.  In the script the source zone area needs to be considered. I could not work out the unit (km?) it needs to be in. In the original paper i believe it is in equatorial degrees squared.  To input the area calculates the a and b values using PML method. 

also can someone confirm whether the  b_prior_weight input should be in log terms (not  percentage/ ratio).   

Is the original publication  (Johnston 1994) used to compute the formulas in this script or a different publication? 

Thanks in advance

Hasib