add accuracy without draws

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "riix"
-version = "0.0.2"
+version = "0.0.3"
 description = "vectorized implementations of online rating systems"
 readme = "README.md"
 license = {file = "LICENSE"}

riix/metrics.py

@@ -11,6 +11,13 @@ def binary_accuracy(probs: np.ndarray, outcomes: np.ndarray) -> float:
     correct = outcomes[pos_mask].sum() + (1.0 - outcomes[neg_mask]).sum() + 0.5 * draw_mask.sum()
     return correct / probs.shape[0]
 
+def accuracy_without_draws(probs: np.ndarray, outcomes: np.ndarray) -> float:
+    """compute binary accuracy after first filtering out rows where the label is a draw"""
+    draw_mask = outcomes == 0.5
+    probs = probs[~draw_mask]
+    outcomes = outcomes[~draw_mask]
+    return binary_accuracy(probs, outcomes)
+
 
 def accuracy_with_draws(probs: np.ndarray, outcomes: np.ndarray, draw_margin=0.0) -> float:
     """computes accuracy while allowing for ties"""
@@ -39,6 +46,7 @@ def binary_metrics_suite(probs: np.ndarray, outcomes: np.ndarray):
     """a wrapper class for running a bunch of binary metrics"""
     metrics = {
         'accuracy': binary_accuracy(probs, outcomes),
+        'accuracy_without_draws' : accuracy_without_draws(probs, outcomes),
         'log_loss': binary_log_loss(probs, outcomes),
         'brier_score': brier_score(probs, outcomes),
     }