diff --git a/mdpow/analysis/automation/dihedral/directory_iteration.py b/mdpow/analysis/automation/dihedral/directory_iteration.py
index 17f1fbf1..149378c9 100644
--- a/mdpow/analysis/automation/dihedral/directory_iteration.py
+++ b/mdpow/analysis/automation/dihedral/directory_iteration.py
@@ -1,11 +1,59 @@
+# MDPOW: directory_iteration.py
+# 2022 Cade Duckworth
+
+import pandas
+
 import automated_dihedral_analysis as ada
 
 
 
-def directory_iteration(dirpaths, figdir=None, padding=45, width=0.9,
+def directory_iteration(directory_paths, figdir=None, padding=45, width=0.9,
                         solvents=('water','octanol'), interactions=('Coulomb','VDW'),
                         start=None, stop=None, step=None):
-    #fix to update how I end up handling arguments
+    '''Takes a Pandas DataFrame created by directory_paths as input
+    and iterates over the provided projects to implement automated_dihedral_analysis
+    for each project directory. Optionally accepts a figure directory for
+    saving plots, and all automated_dihedral_analysis and DihedralAnalysis
+    keyword arguments. Extracts molname, resname, and datadir from 
+    directory_paths Pandas DataFrame for use in obtaining dihedral groups
+    and plotting dihedral angle frequency KDEs.
+    
+    :keywords:
+    
+    *figdir : string*
+        optional, path to existing directory where plots
+        can be saved for each MDPOW project analyzed
+        
+    *padding : int*
+        must be in degrees, values for angle padding function
+        used for KDE violin plots of dihedral angle frequencies
+        
+    *width : float*
+        used for violin plots
+        width of violins, (>1 overlaps)
+        see automated_dihedral_analysis.dihedral_violins
+        
+    *solvents : tuple*
+        solvent specifications for use with DihedralAnalysis
+        see automated_dihedral_analysis
+        
+    *interactions : tuple*
+        interaction specifications for use with DihedralAnalysis
+        see automated_dihedral_analysis
+        
+    *start,stop,step : int*
+        run frame analysis parameters for use with DihedralAnalysis
+        see automated_dihedral_analysis
+        
+    Example:
+       
+           directory_paths = directory_paths(parent_directory='/foo/bar/MDPOW_projects')
+           directory_iteration(directory_paths, figdir='/foo/bar/figure_directory,
+                               padding=45, width=0.9,
+                               solvents=('water','octanol'), interactions=('Coulomb','VDW'),
+                               start=0, stop=100, step=10)
+           
+    '''
 
     for row in dirpaths.itertuples():
             molname = row.molecule