IntersectionDataset: better error message when no overlap (microsoft#…

…1192)

* IntersectionDataset: better error message when no overlap

* Update split tests

* Document error

tests/datasets/test_geo.py

@@ -405,10 +405,20 @@ def test_nongeo_dataset(self) -> None:
             IntersectionDataset(ds1, ds2)  # type: ignore[arg-type]
 
     def test_different_crs(self) -> None:
-        ds1 = CustomGeoDataset(crs=CRS.from_epsg(3005))
-        ds2 = CustomGeoDataset(crs=CRS.from_epsg(32616))
+        ds1 = CustomGeoDataset(BoundingBox(0, 1, 0, 1, 0, 1), crs=CRS.from_epsg(3005))
+        ds2 = CustomGeoDataset(
+            BoundingBox(
+                -3547229.913123814,
+                6360089.518213182,
+                -3547229.913123814,
+                6360089.518213182,
+                -3547229.913123814,
+                6360089.518213182,
+            ),
+            crs=CRS.from_epsg(32616),
+        )
         ds = IntersectionDataset(ds1, ds2)
-        assert len(ds) == 0
+        assert len(ds) == 1
 
     def test_different_res(self) -> None:
         ds1 = CustomGeoDataset(res=1)
@@ -419,8 +429,9 @@ def test_different_res(self) -> None:
     def test_no_overlap(self) -> None:
         ds1 = CustomGeoDataset(BoundingBox(0, 1, 2, 3, 4, 5))
         ds2 = CustomGeoDataset(BoundingBox(6, 7, 8, 9, 10, 11))
-        ds = IntersectionDataset(ds1, ds2)
-        assert len(ds) == 0
+        msg = "Datasets have no spatiotemporal intersection"
+        with pytest.raises(RuntimeError, match=msg):
+            IntersectionDataset(ds1, ds2)
 
     def test_invalid_query(self, dataset: IntersectionDataset) -> None:
         query = BoundingBox(0, 0, 0, 0, 0, 0)

tests/datasets/test_splits.py

@@ -18,6 +18,23 @@
 )
 
 
+def total_area(dataset: GeoDataset) -> float:
+    total_area = 0.0
+    for hit in dataset.index.intersection(dataset.index.bounds, objects=True):
+        total_area += BoundingBox(*hit.bounds).area
+
+    return total_area
+
+
+def no_overlap(ds1: GeoDataset, ds2: GeoDataset) -> bool:
+    try:
+        ds = ds1 & ds2
+    except RuntimeError:
+        return True
+    else:
+        return isclose(total_area(ds), 0)
+
+
 class CustomGeoDataset(GeoDataset):
     def __init__(
         self,
@@ -66,11 +83,9 @@ def test_random_bbox_assignment(
     assert len(test_ds) == expected_lengths[2]
 
     # No overlap
-    assert len(train_ds & val_ds) == 0 or isclose(_get_total_area(train_ds & val_ds), 0)
-    assert len(val_ds & test_ds) == 0 or isclose(_get_total_area(val_ds & test_ds), 0)
-    assert len(test_ds & train_ds) == 0 or isclose(
-        _get_total_area(test_ds & train_ds), 0
-    )
+    assert no_overlap(train_ds, val_ds)
+    assert no_overlap(val_ds, test_ds)
+    assert no_overlap(test_ds, train_ds)
 
     # Union equals original
     assert (train_ds | val_ds | test_ds).bounds == ds.bounds
@@ -93,14 +108,6 @@ def test_random_bbox_assignment_invalid_inputs() -> None:
         random_bbox_assignment(CustomGeoDataset(), lengths=[1 / 2, 3 / 4, -1 / 4])
 
 
-def _get_total_area(dataset: GeoDataset) -> float:
-    total_area = 0.0
-    for hit in dataset.index.intersection(dataset.index.bounds, objects=True):
-        total_area += BoundingBox(*hit.bounds).area
-
-    return total_area
-
-
 def test_random_bbox_splitting() -> None:
     ds = CustomGeoDataset(
         [
@@ -111,30 +118,28 @@ def test_random_bbox_splitting() -> None:
         ]
     )
 
-    ds_area = _get_total_area(ds)
+    ds_area = total_area(ds)
 
     train_ds, val_ds, test_ds = random_bbox_splitting(
         ds, fractions=[1 / 2, 1 / 4, 1 / 4]
     )
-    train_ds_area = _get_total_area(train_ds)
-    val_ds_area = _get_total_area(val_ds)
-    test_ds_area = _get_total_area(test_ds)
+    train_ds_area = total_area(train_ds)
+    val_ds_area = total_area(val_ds)
+    test_ds_area = total_area(test_ds)
 
     # Check datasets areas
     assert train_ds_area == ds_area / 2
     assert val_ds_area == ds_area / 4
     assert test_ds_area == ds_area / 4
 
     # No overlap
-    assert len(train_ds & val_ds) == 0 or isclose(_get_total_area(train_ds & val_ds), 0)
-    assert len(val_ds & test_ds) == 0 or isclose(_get_total_area(val_ds & test_ds), 0)
-    assert len(test_ds & train_ds) == 0 or isclose(
-        _get_total_area(test_ds & train_ds), 0
-    )
+    assert no_overlap(train_ds, val_ds)
+    assert no_overlap(val_ds, test_ds)
+    assert no_overlap(test_ds, train_ds)
 
     # Union equals original
     assert (train_ds | val_ds | test_ds).bounds == ds.bounds
-    assert isclose(_get_total_area(train_ds | val_ds | test_ds), ds_area)
+    assert isclose(total_area(train_ds | val_ds | test_ds), ds_area)
 
     # Test __get_item__
     x = train_ds[train_ds.bounds]
@@ -168,15 +173,13 @@ def test_random_grid_cell_assignment() -> None:
     assert len(test_ds) == floor(1 / 4 * 2 * 5**2)
 
     # No overlap
-    assert len(train_ds & val_ds) == 0 or isclose(_get_total_area(train_ds & val_ds), 0)
-    assert len(val_ds & test_ds) == 0 or isclose(_get_total_area(val_ds & test_ds), 0)
-    assert len(test_ds & train_ds) == 0 or isclose(
-        _get_total_area(test_ds & train_ds), 0
-    )
+    assert no_overlap(train_ds, val_ds)
+    assert no_overlap(val_ds, test_ds)
+    assert no_overlap(test_ds, train_ds)
 
     # Union equals original
     assert (train_ds | val_ds | test_ds).bounds == ds.bounds
-    assert isclose(_get_total_area(train_ds | val_ds | test_ds), _get_total_area(ds))
+    assert isclose(total_area(train_ds | val_ds | test_ds), total_area(ds))
 
     # Test __get_item__
     x = train_ds[train_ds.bounds]
@@ -219,15 +222,13 @@ def test_roi_split() -> None:
     assert len(test_ds) == 1
 
     # No overlap
-    assert len(train_ds & val_ds) == 0 or isclose(_get_total_area(train_ds & val_ds), 0)
-    assert len(val_ds & test_ds) == 0 or isclose(_get_total_area(val_ds & test_ds), 0)
-    assert len(test_ds & train_ds) == 0 or isclose(
-        _get_total_area(test_ds & train_ds), 0
-    )
+    assert no_overlap(train_ds, val_ds)
+    assert no_overlap(val_ds, test_ds)
+    assert no_overlap(test_ds, train_ds)
 
     # Union equals original
     assert (train_ds | val_ds | test_ds).bounds == ds.bounds
-    assert isclose(_get_total_area(train_ds | val_ds | test_ds), _get_total_area(ds))
+    assert isclose(total_area(train_ds | val_ds | test_ds), total_area(ds))
 
     # Test __get_item__
     x = train_ds[train_ds.bounds]
@@ -273,9 +274,9 @@ def test_time_series_split(
     assert len(test_ds) == expected_lengths[2]
 
     # No overlap
-    assert len(train_ds & val_ds) == 0
-    assert len(val_ds & test_ds) == 0
-    assert len(test_ds & train_ds) == 0
+    assert no_overlap(train_ds, val_ds)
+    assert no_overlap(val_ds, test_ds)
+    assert no_overlap(test_ds, train_ds)
 
     # Union equals original
     assert (train_ds | val_ds | test_ds).bounds == ds.bounds

torchgeo/datasets/geo.py

@@ -811,6 +811,7 @@ def __init__(
                 entry and returns a transformed version
 
         Raises:
+            RuntimeError: if datasets have no spatiotemporal intersection
             ValueError: if either dataset is not a :class:`GeoDataset`
 
         .. versionadded:: 0.4
@@ -855,6 +856,9 @@ def _merge_dataset_indices(self) -> None:
                 self.index.insert(i, tuple(box1 & box2))
                 i += 1
 
+        if i == 0:
+            raise RuntimeError("Datasets have no spatiotemporal intersection")
+
     def __getitem__(self, query: BoundingBox) -> Dict[str, Any]:
         """Retrieve image and metadata indexed by query.