changed helpers/statistics.py 279 AND 305 ahead_names to the actual times,...

changed helpers/statistics.py 279 AND 305 ahead_names to the actual times, because non monotonically rising window lead times can occur (it was a simple range before)

mlair/helpers/statistics.py

@@ -276,7 +276,7 @@ class SkillScores:
 
         :return: skill score for each comparison and forecast step
         """
-        ahead_names = list(range(1, window_lead_time + 1))
+        ahead_names = list(self.external_data.ahead.data)
         combinations, combination_strings = self.get_model_name_combinations()
         skill_score = pd.DataFrame(index=combination_strings)
         for iahead in ahead_names:
@@ -302,7 +302,7 @@ class SkillScores:
 
         :return: all CASES as well as all terms
         """
-        ahead_names = list(range(1, window_lead_time + 1))
+        ahead_names = list(self.external_data.ahead.data)
 
         all_terms = ['AI', 'AII', 'AIII', 'AIV', 'BI', 'BII', 'BIV', 'CI', 'CIV', 'CASE I', 'CASE II', 'CASE III',
                      'CASE IV']