Add from_linestrings_xy and from_polygons_xy (#928)

Provides public GeoSeries methods to create single-type GeoSeries for linestrings and polygons in addition to the points and multipoints methods added in #924.

Authors:
  - H. Thomson Comer (https://github.com/thomcom)
  - Michael Wang (https://github.com/isVoid)

Approvers:
  - Michael Wang (https://github.com/isVoid)
  - Mark Harris (https://github.com/harrism)

URL: #928

python/cuspatial/cuspatial/core/_column/geocolumn.py

@@ -288,6 +288,130 @@ def _from_multipoints_xy(
             meta,
         )
 
+    @classmethod
+    def _from_linestrings_xy(
+        cls,
+        linestrings_xy: ColumnBase,
+        part_offsets: ColumnBase,
+        geometry_offsets: ColumnBase,
+    ):
+        """
+        Create a GeoColumn of multilinestrings from a cudf Series with
+        interleaved xy coordinates.
+        """
+        if not linestrings_xy.dtype.kind == "f":
+            raise ValueError("Coordinates must be floating point numbers.")
+
+        parts_col = build_list_column(
+            indices=part_offsets,
+            elements=_xy_as_variable_sized_list(linestrings_xy),
+            size=len(part_offsets) - 1,
+        )
+        linestrings_col = build_list_column(
+            indices=geometry_offsets,
+            elements=parts_col,
+            size=len(geometry_offsets) - 1,
+        )
+        num_linestrings = len(linestrings_col)
+
+        meta = GeoMeta(
+            {
+                "input_types": as_column(
+                    cp.full(
+                        num_linestrings,
+                        Feature_Enum.LINESTRING.value,
+                        dtype=cp.int8,
+                    )
+                ),
+                "union_offsets": as_column(
+                    cp.arange(num_linestrings, dtype=cp.int32)
+                ),
+            }
+        )
+
+        coord_dtype = linestrings_xy.dtype
+
+        return cls(
+            (
+                cudf.Series(
+                    empty_geometry_column(Feature_Enum.POINT, coord_dtype)
+                ),
+                cudf.Series(
+                    empty_geometry_column(Feature_Enum.MULTIPOINT, coord_dtype)
+                ),
+                cudf.Series(linestrings_col),
+                cudf.Series(
+                    empty_geometry_column(Feature_Enum.POLYGON, coord_dtype)
+                ),
+            ),
+            meta,
+        )
+
+    @classmethod
+    def _from_polygons_xy(
+        cls,
+        polygons_xy: ColumnBase,
+        ring_offsets: ColumnBase,
+        part_offsets: ColumnBase,
+        geometry_offsets: ColumnBase,
+    ):
+        """
+        Create a GeoColumn of multipolygons from a cudf Series with
+        interleaved xy coordinates.
+        """
+        if not polygons_xy.dtype.kind == "f":
+            raise ValueError("Coordinates must be floating point numbers.")
+
+        rings_col = build_list_column(
+            indices=ring_offsets,
+            elements=_xy_as_variable_sized_list(polygons_xy),
+            size=len(ring_offsets) - 1,
+        )
+        parts_col = build_list_column(
+            indices=part_offsets,
+            elements=rings_col,
+            size=len(part_offsets) - 1,
+        )
+        polygons_col = build_list_column(
+            indices=geometry_offsets,
+            elements=parts_col,
+            size=len(geometry_offsets) - 1,
+        )
+        num_polygons = len(polygons_col)
+
+        meta = GeoMeta(
+            {
+                "input_types": as_column(
+                    cp.full(
+                        num_polygons,
+                        Feature_Enum.POLYGON.value,
+                        dtype=cp.int8,
+                    )
+                ),
+                "union_offsets": as_column(
+                    cp.arange(num_polygons, dtype=cp.int32)
+                ),
+            }
+        )
+
+        coord_dtype = polygons_xy.dtype
+
+        return cls(
+            (
+                cudf.Series(
+                    empty_geometry_column(Feature_Enum.POINT, coord_dtype)
+                ),
+                cudf.Series(
+                    empty_geometry_column(Feature_Enum.MULTIPOINT, coord_dtype)
+                ),
+                cudf.Series(
+                    empty_geometry_column(Feature_Enum.LINESTRING, coord_dtype)
+                ),
+                cudf.Series(polygons_col),
+            ),
+            meta,
+        )
+
     @cached_property
     def memory_usage(self) -> int:
         """

python/cuspatial/cuspatial/core/geoseries.py

@@ -630,8 +630,8 @@ def from_points_xy(cls, points_xy):
     @classmethod
     def from_multipoints_xy(cls, multipoints_xy, geometry_offset):
         """
-        Construct a GeoSeries of MULTIPOINTs from an array of interleaved xy
-        coordinates.
+        Construct a GeoSeries of MULTIPOINTs from an array of interleaved
+        xy coordinates.
 
         Parameters
         ----------
@@ -663,6 +663,103 @@ def from_multipoints_xy(cls, multipoints_xy, geometry_offset):
             )
         )
 
+    @classmethod
+    def from_linestrings_xy(
+        cls, linestrings_xy, part_offset, geometry_offset
+    ) -> T:
+        """
+        Construct a GeoSeries of MULTILINESTRINGs from an array of interleaved
+        xy coordinates.
+
+        Parameters
+        ----------
+        linestrings_xy : array-like
+            Coordinates of the points, interpreted as interleaved x-y coords.
+        geometry_offset : array-like
+            Offsets of the first coordinate of each geometry. The length of
+            this array is the number of geometries.  Offsets with a difference
+            greater than 1 indicate a MultiLinestring.
+        part_offset : array-like
+            Offsets into the coordinates array indicating the beginning of
+            each part. The length of this array is the number of parts.
+
+        Returns
+        -------
+        GeoSeries:
+            A GeoSeries of MULTILINESTRINGs.
+
+        Example
+        -------
+        >>> import cudf
+        >>> import cuspatial
+        >>> linestrings_xy = cudf.Series(
+                [0.0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5])
+        >>> part_offset = cudf.Series([0, 6])
+        >>> geometry_offset = cudf.Series([0, 1])
+        >>> cuspatial.GeoSeries.from_linestrings_xy(
+                linestrings_xy, part_offset, geometry_offset)
+        0    LINESTRING (0 0, 1 1, 2 2, 3 3, 4 4, 5 5)
+        dtype: geometry
+        """
+        return cls(
+            GeoColumn._from_linestrings_xy(
+                as_column(linestrings_xy),
+                as_column(part_offset, dtype="int32"),
+                as_column(geometry_offset, dtype="int32"),
+            )
+        )
+
+    @classmethod
+    def from_polygons_xy(
+        cls, polygons_xy, ring_offset, part_offset, geometry_offset
+    ) -> T:
+        """
+        Construct a GeoSeries of MULTIPOLYGONs from an array of interleaved xy
+        coordinates.
+
+        Parameters
+        ----------
+        polygons_xy : array-like
+            Coordinates of the points, interpreted as interleaved x-y coords.
+        geometry_offset : array-like
+            Offsets of the first coordinate of each geometry. The length of
+            this array is the number of geometries.  Offsets with a difference
+            greater than 1 indicate a MultiLinestring.
+        part_offset : array-like
+            Offsets into the coordinates array indicating the beginning of
+            each part. The length of this array is the number of parts.
+        rint_offset : array-like
+            Offsets into the part array indicating the beginning of each ring.
+            The length of this array is the number of rings.
+
+        Returns
+        -------
+        GeoSeries:
+            A GeoSeries of MULTIPOLYGONs.
+
+        Example
+        -------
+        >>> import cudf
+        >>> import cuspatial
+        >>> polygons_xy = cudf.Series(
+                [0.0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5])
+        >>> ring_offset = cudf.Series([0, 6])
+        >>> part_offset = cudf.Series([0, 1])
+        >>> geometry_offset = cudf.Series([0, 1])
+        >>> cuspatial.GeoSeries.from_polygons_xy(
+                polygons_xy, ring_offset, part_offset, geometry_offset)
+        0    POLYGON (0 0, 1 1, 2 2, 3 3, 4 4, 5 5)
+        dtype: geometry
+        """
+        return cls(
+            GeoColumn._from_polygons_xy(
+                as_column(polygons_xy),
+                as_column(ring_offset, dtype="int32"),
+                as_column(part_offset, dtype="int32"),
+                as_column(geometry_offset, dtype="int32"),
+            )
+        )
+
     def align(self, other):
         """
         Align the rows of two GeoSeries using outer join.

python/cuspatial/cuspatial/tests/test_geoseries.py

@@ -736,3 +736,62 @@ def test_from_multipoints_xy(multipoint_generator):
     )
 
     gpd.testing.assert_geoseries_equal(hs, gs2.to_geopandas())
+
+
+def test_from_linestrings_xy(linestring_generator):
+    hs = gpd.GeoSeries(linestring_generator(10, 10))
+    gs = cuspatial.from_geopandas(hs)
+
+    gs2 = cuspatial.GeoSeries.from_linestrings_xy(
+        gs.lines.xy, gs.lines.part_offset, gs.lines.geometry_offset
+    )
+
+    gpd.testing.assert_geoseries_equal(hs, gs2.to_geopandas())
+
+
+def test_from_polygons_xy(polygon_generator):
+    hs = gpd.GeoSeries(polygon_generator(10, 10))
+    gs = cuspatial.from_geopandas(hs)
+
+    gs2 = cuspatial.GeoSeries.from_polygons_xy(
+        gs.polygons.xy,
+        gs.polygons.ring_offset,
+        gs.polygons.part_offset,
+        gs.polygons.geometry_offset,
+    )
+
+    gpd.testing.assert_geoseries_equal(hs, gs2.to_geopandas())
+
+
+def test_from_linestrings_xy_example():
+    linestrings_xy = cudf.Series([0.0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5])
+    part_offset = cudf.Series([0, 6])
+    geometry_offset = cudf.Series([0, 1])
+    gline = cuspatial.GeoSeries.from_linestrings_xy(
+        linestrings_xy, part_offset, geometry_offset
+    )
+    hline = gpd.GeoSeries(
+        [
+            LineString([(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5)]),
+        ]
+    )
+    gpd.testing.assert_geoseries_equal(
+        gline.to_geopandas(), hline, check_less_precise=True
+    )
+
+
+def test_from_polygons_xy_example():
+    polygons_xy = cudf.Series([0.0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 0, 0])
+    ring_offset = cudf.Series([0, 6])
+    part_offset = cudf.Series([0, 1])
+    geometry_offset = cudf.Series([0, 1])
+    gpolygon = cuspatial.GeoSeries.from_polygons_xy(
+        polygons_xy,
+        ring_offset,
+        part_offset,
+        geometry_offset,
+    )
+    hpolygon = gpd.GeoSeries(
+        [Polygon([(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (0, 0)])]
+    )
+    gpd.testing.assert_geoseries_equal(gpolygon.to_geopandas(), hpolygon)