Update subsampling.py

src/alchemlyb/preprocessing/subsampling.py

@@ -58,7 +58,8 @@ def slicing(df, lower=None, upper=None, step=None, force=False):
 
 
 def statistical_inefficiency(df, series=None, lower=None, upper=None, step=None,
-                             conservative=True, drop_duplicates=False, sort=False):
+                             conservative=True, drop_duplicates=False, sort=False,
+                             method='dhdl'):
     """Subsample a DataFrame based on the calculated statistical inefficiency
     of a timeseries.
 
@@ -123,6 +124,19 @@ def statistical_inefficiency(df, series=None, lower=None, upper=None, step=None,
        end up with correlated data.
 
     """
+
+    if method == 'dhdl':
+        # Find the current column index
+        # Select the first row and remove the first column (Time)
+        key = u_nk.index.values[0][1:]
+                    if len(key) > 1:
+                        # Multiple keys
+                        col = u_nk[key]
+                    else:
+                        # Single key
+                        col = u_nk[key[0]]
+                    subsample = statistical_inefficiency(u_nk, col, sort=True,
+                                                         drop_duplicates=True)
     if _check_multiple_times(df):
         if drop_duplicates:
             if isinstance(df, pd.Series):