Skip full-raster geodesic memory guard for dask aspect

xrspatial/aspect.py

@@ -19,7 +19,7 @@
                                 _cpu_geodesic_aspect, _run_gpu_geodesic_aspect)
 from xrspatial.utils import (Z_UNITS, ArrayTypeFunctionMapping, _boundary_to_dask,
                              _extract_latlon_coords, _pad_array, _validate_boundary,
-                             _validate_raster, cuda_args, ngjit)
+                             _validate_raster, cuda_args, has_dask_array, ngjit)
 
 
 def _geodesic_cuda_dims(shape):
@@ -423,8 +423,14 @@ def aspect(agg: xr.DataArray,
             )
         z_factor = Z_UNITS[z_unit]
 
-        rows, cols = agg.shape[-2], agg.shape[-1]
-        _check_geodesic_memory(rows, cols, func_name='aspect')
+        # The full-raster memory guard only applies to in-memory (numpy/cupy)
+        # arrays, which materialize the whole (3, H, W) stack at once. Dask
+        # backends process the raster chunk-by-chunk via map_overlap, so peak
+        # memory is bounded by chunk size, not full-raster size.
+        is_dask = has_dask_array() and isinstance(agg.data, da.Array)
+        if not is_dask:
+            rows, cols = agg.shape[-2], agg.shape[-1]
+            _check_geodesic_memory(rows, cols, func_name='aspect')
 
         lat_2d, lon_2d = _extract_latlon_coords(agg)
 

xrspatial/tests/test_geodesic_aspect.py

@@ -257,6 +257,41 @@ def test_planar_method_skips_guard(self, monkeypatch):
         result = aspect(raster, method='planar')
         assert result.shape == (8, 8)
 
+    @dask_array_available
+    def test_dask_chunked_skips_full_raster_guard(self, monkeypatch):
+        """A chunked dask raster is processed chunk-by-chunk via map_overlap,
+        so the full-raster guard must not reject it even when available memory
+        is tiny (issue #2763)."""
+        monkeypatch.setattr(
+            'xrspatial.geodesic._available_memory_bytes', lambda: 1024 * 1024
+        )
+        elev = _flat_surface(H=200, W=200)
+        raster = _make_geo_raster(
+            elev, 40.0, 41.0, 10.0, 11.0,
+            backend='dask+numpy', chunks=(40, 40),
+        )
+        result = aspect(raster, method='geodesic')
+        # Force evaluation to confirm the chunked path actually runs.
+        computed = result.compute()
+        assert computed.shape == (200, 200)
+
+    @dask_array_available
+    @cuda_and_cupy_available
+    def test_dask_cupy_chunked_skips_full_raster_guard(self, monkeypatch):
+        """dask+cupy goes through the same chunked map_overlap path, so the
+        full-raster guard must not reject it either (issue #2763)."""
+        monkeypatch.setattr(
+            'xrspatial.geodesic._available_memory_bytes', lambda: 1024 * 1024
+        )
+        elev = _flat_surface(H=200, W=200)
+        raster = _make_geo_raster(
+            elev, 40.0, 41.0, 10.0, 11.0,
+            backend='dask+cupy', chunks=(40, 40),
+        )
+        result = aspect(raster, method='geodesic')
+        computed = result.compute()
+        assert computed.shape == (200, 200)
+
 
 # ---------------------------------------------------------------------------
 # Tests — cross-backend consistency