no attribute fitters_ZPK

Created by: ldartez

Running the line below produces the following error:

File c:\users\cad3r\desktop\python data\caden swain transfer function fitting.py:104
    coding_map = wield.iirrational.fitters_ZPK.mappings.coding_maps.nlFBW)

AttributeError: module 'wield.iirrational' has no attribute 'fitters_ZPK'