pre-compute inputs in Dask test functions

tests/python_package_test/test_dask.py

@@ -213,13 +213,17 @@ def _create_data(objective, n_samples=1_000, output="array", chunk_size=500, **k
 
 
 def _r2_score(dy_true, dy_pred):
-    numerator = ((dy_true - dy_pred) ** 2).sum(axis=0, dtype=np.float64)
-    denominator = ((dy_true - dy_true.mean(axis=0)) ** 2).sum(axis=0, dtype=np.float64)
-    return (1 - numerator / denominator).compute()
+    y_true = dy_true.compute()
+    y_pred = dy_pred.compute()
+    numerator = ((y_true - y_pred) ** 2).sum(axis=0)
+    denominator = ((y_true - y_true.mean(axis=0)) ** 2).sum(axis=0)
+    return 1 - numerator / denominator
 
 
 def _accuracy_score(dy_true, dy_pred):
-    return da.average(dy_true == dy_pred).compute()
+    y_true = dy_true.compute()
+    y_pred = dy_pred.compute()
+    return (y_true == y_pred).mean()
 
 
 def _constant_metric(y_true, y_pred):