Bugfix: reset should set clear _computed (#147)

* Bugfix: reset should set clear _computed

* changelog

* Update CHANGELOG.md

Co-authored-by: Nicki Skafte <skaftenicki@gmail.com>

CHANGELOG.md

@@ -63,6 +63,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed when `_stable_1d_sort` to work when n >= N ([#6177](https://github.com/PyTorchLightning/pytorch-lightning/pull/6177))
 
 
+- Fixed `_computed` attribute not being correctly reset ([#147](https://github.com/PyTorchLightning/metrics/pull/147))
+
+
 ## [0.2.0] - 2021-03-12
 
 

tests/bases/test_metric.py

@@ -95,6 +95,15 @@ def test_reset():
     assert isinstance(b.x, list) and len(b.x) == 0
 
 
+def test_reset_compute():
+    a = DummyMetricSum()
+    assert a.x == 0
+    a.update(tensor(5))
+    assert a.compute() == 5
+    a.reset()
+    assert a.compute() == 0
+
+
 def test_update():
 
     class A(DummyMetric):

torchmetrics/metric.py

@@ -254,6 +254,8 @@ class Metric(nn.Module, ABC):
         """
         This method automatically resets the metric state variables to their default value.
         """
+        self._computed = None
+
         for attr, default in self._defaults.items():
             current_val = getattr(self, attr)
             if isinstance(default, Tensor):