added warning for fit method

hpfrec/__init__.py

@@ -43,6 +43,11 @@ class HPF:
     For slighly better speed pass verbose=False once you know what a good threshold should be
     for your data.
 
+    Note
+    ----
+    DataFrames and arrays passed to '.fit' might be modified inplace - if this is a problem you'll
+    need to pass a copy to them, e.g. 'counts_df=counts_df.copy()'.
+
     Note
     ----
     If 'check_every' is not None and stop_crit is not 'diff-norm', it will, every N iterations,
@@ -305,8 +310,14 @@ def fit(self, counts_df, val_set=None):
         
         Note
         ----
-        Forcibly terminating the procedure should still keep the last calculated Theta and Beta in the
-        object attributes, but is not recommended.
+        DataFrames and arrays passed to '.fit' might be modified inplace - if this is a problem you'll
+        need to pass a copy to them, e.g. 'counts_df=counts_df.copy()'.
+
+        Note
+        ----
+        Forcibly terminating the procedure should still keep the last calculated shape and rate
+        parameter values, but is not recommended. If you need to make predictions on a forced-terminated
+        object, set the attribute 'is_fitted' to 'True'.
 
         Parameters
         ----------