Merge pull request #113 from DoubleML/m-prevent-warning-by-initial-with-nan

by initializing with nan instead of zero, we no longer get divide by zero warnings when running IRM with ATTE score without cross-fitting

Author: MalteKurz

doubleml/double_ml_irm.py

@@ -192,7 +192,7 @@ def _score_elements(self, y, d, g_hat0, g_hat1, m_hat, smpls):
         # fraction of treated for ATTE
         p_hat = None
         if self.score == 'ATTE':
-            p_hat = np.zeros_like(d, dtype='float64')
+            p_hat = np.full_like(d, np.nan, dtype='float64')
             for _, test_index in smpls:
                 p_hat[test_index] = np.mean(d[test_index])