Supress warning for running metric wrapper

CHANGELOG.md

@@ -51,7 +51,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
--
+- Fixed warning incorrectly being raised in `Running` metrics ([#2256](https://github.com/Lightning-AI/torchmetrics/pull/2265))
 
 
 ## [1.2.1] - 2023-11-30

src/torchmetrics/metric.py

@@ -592,7 +592,7 @@ def sync_context(
     def _wrap_compute(self, compute: Callable) -> Callable:
         @functools.wraps(compute)
         def wrapped_func(*args: Any, **kwargs: Any) -> Any:
-            if self._update_count == 0:
+            if not self.update_called:
                 rank_zero_warn(
                     f"The ``compute`` method of metric {self.__class__.__name__}"
                     " was called before the ``update`` method which may lead to errors,"

src/torchmetrics/wrappers/running.py

@@ -127,6 +127,7 @@ def compute(self) -> Any:
         """Compute the metric over the running window."""
         for i in range(self.window):
             self.base_metric._reduce_states({key: getattr(self, key + f"_{i}") for key in self.base_metric._defaults})
+        self.base_metric._update_count = self._num_vals_seen
         val = self.base_metric.compute()
         self.base_metric.reset()
         return val

tests/unittests/wrappers/test_running.py

@@ -23,6 +23,7 @@
 from torchmetrics.wrappers import Running
 
 from unittests import NUM_PROCESSES
+from unittests.helpers.utilities import no_warning_call
 
 
 def test_errors_on_wrong_input():
@@ -150,3 +151,11 @@ def test_ddp_running(dist_sync_on_step, expected):
     pytest.pool.map(
         partial(_test_ddp_running, dist_sync_on_step=dist_sync_on_step, expected=expected), range(NUM_PROCESSES)
     )
+
+
+def test_no_warning_due_to_reset():
+    """Internally we call .reset() which would normally raise a warning, but it should not happen in Runner."""
+    metric = Running(SumMetric(), window=3)
+    metric.update(torch.tensor(2.0))
+    with no_warning_call(UserWarning):
+        metric.compute()