BUG: Use @ instead of * for Affine multiplication (#937)

docs/history.rst

@@ -3,6 +3,9 @@ History
 
 Latest
 ------
+- BUG: Use ``@`` instead of ``*`` for ``Affine`` multiplication to avoid
+  affine 3.0.1 ``PendingDeprecationWarning`` (issue #937)
+- DEP: Add explicit ``affine>=3.0`` dependency (issue #937)
 
 0.23.0
 ------

pyproject.toml

@@ -33,6 +33,7 @@ classifiers = [
 ]
 requires-python = ">=3.12"
 dependencies = [
+    "affine>=3.0",
     "packaging",
     "rasterio>=1.4.3",
     # https://github.com/pydata/xarray/issues/11000

rioxarray/_spatial_utils.py

@@ -114,16 +114,16 @@ def affine_to_coords(
     dict: x and y coordinate arrays.
 
     """
-    transform = affine * affine.translation(0.5, 0.5)
+    transform = affine @ affine.translation(0.5, 0.5)
     if affine.is_rectilinear and not _affine_has_rotation(affine):
-        x_coords, _ = transform * (numpy.arange(width), numpy.zeros(width))
-        _, y_coords = transform * (numpy.zeros(height), numpy.arange(height))
+        x_coords, _ = transform @ (numpy.arange(width), numpy.zeros(width))
+        _, y_coords = transform @ (numpy.zeros(height), numpy.arange(height))
     else:
-        x_coords, y_coords = transform * numpy.meshgrid(
+        x_coords, y_coords = transform @ numpy.meshgrid(
             numpy.arange(width),
             numpy.arange(height),
         )
-    return {y_dim: y_coords, x_dim: x_coords}
+    return {y_dim: numpy.asarray(y_coords), x_dim: numpy.asarray(x_coords)}
 
 
 def _generate_spatial_coords(

rioxarray/rioxarray.py

@@ -439,7 +439,7 @@ def transform(self, recalc: bool = False) -> Affine:
             src_resolution_x, src_resolution_y = self.resolution(recalc=recalc)
         except (DimensionMissingCoordinateError, DimensionError):
             return Affine.identity() if transform is None else transform
-        return Affine.translation(src_left, src_top) * Affine.scale(
+        return Affine.translation(src_left, src_top) @ Affine.scale(
             src_resolution_x, src_resolution_y
         )
 

test/integration/test_integration__io.py

@@ -1612,3 +1612,32 @@ def test_reading_writing_rpcs(tmp_path):
         assert (
             dst.rpcs is not None
         ), "Existing RPCs in dst raster (through rpc attribute)"
+
+
+@pytest.mark.parametrize(
+    "transform",
+    [Affine(1, 0, 0, 0, -1, 4), Affine(1, 0.5, 0, 0.5, -1, 4)],
+    ids=["rectilinear", "rotated"],
+)
+def test_open_rasterio__no_affine_mul_warning(transform):
+    # https://github.com/corteva/rioxarray/issues/937
+    with rasterio.MemoryFile() as memfile:
+        with memfile.open(
+            driver="GTiff",
+            height=4,
+            width=4,
+            count=1,
+            dtype="uint8",
+            crs="EPSG:4326",
+            transform=transform,
+        ) as dataset:
+            dataset.write(numpy.zeros((1, 4, 4), dtype="uint8"))
+        with warnings.catch_warnings():
+            warnings.filterwarnings(
+                "error",
+                message="Use `@` matmul",
+                category=PendingDeprecationWarning,
+            )
+            with memfile.open() as dataset:
+                rds = rioxarray.open_rasterio(dataset)
+            rds.rio.transform(recalc=True)