Chunked Geometry Arrays¶
Chunked arrays of geospatial geometries, each of the same type.
ChunkedPointArray
ChunkedLineStringArray
ChunkedPolygonArray
ChunkedMultiPointArray
ChunkedMultiLineStringArray
ChunkedMultiPolygonArray
ChunkedMixedGeometryArray
ChunkedGeometryCollectionArray
ChunkedWKBArray
ChunkedRectArray
geoarrow.rust.core ¶
ChunkedPointArray ¶
An immutable chunked array of Point geometries using GeoArrow's in-memory representation.
area
method descriptor
¶
area() -> ChunkedFloat64Array
Unsigned planar area of a geometry array
Returns:
-
ChunkedFloat64Array
–Chunked array with area values.
center
method descriptor
¶
center() -> ChunkedPointArray
Compute the center of geometries
This first computes the axis-aligned bounding rectangle, then takes the center of that box
Returns:
-
ChunkedPointArray
–Array with center values.
centroid
method descriptor
¶
centroid() -> ChunkedPointArray
Calculation of the centroid.
The centroid is the arithmetic mean position of all points in the shape. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin.
The geometric centroid of a convex object always lies in the object. A non-convex object might have a centroid that is outside the object itself.
Returns:
-
ChunkedPointArray
–Array with centroid values.
chamberlain_duquette_signed_area
method descriptor
¶
chamberlain_duquette_signed_area() -> ChunkedFloat64Array
Calculate the signed approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chamberlain_duquette_unsigned_area
method descriptor
¶
chamberlain_duquette_unsigned_area() -> ChunkedFloat64Array
Calculate the unsigned approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
concatenate
method descriptor
¶
concatenate() -> PointArray
Concatenate a chunked array into a contiguous array.
convex_hull
method descriptor
¶
convex_hull() -> ChunkedPolygonArray
Returns the convex hull of a Polygon. The hull is always oriented counter-clockwise.
This implementation uses the QuickHull algorithm, based on Barber, C. Bradford; Dobkin, David P.; Huhdanpaa, Hannu (1 December 1996) Original paper here: www.cs.princeton.edu/~dpd/Papers/BarberDobkinHuhdanpaa.pdf
Returns:
-
ChunkedPolygonArray
–Array with convex hull polygons.
envelope
method descriptor
¶
envelope()
Computes the minimum axis-aligned bounding box that encloses an input geometry
Returns:
-
–
Array with axis-aligned bounding boxes.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self
geodesic_area_signed
method descriptor
¶
geodesic_area_signed() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Feature standard. Alternative windings may result in a negative area. See "Interpreting negative area values" below.
- Polygons are assumed to be smaller than half the size of the earth. If you expect to be dealing
with polygons larger than this, please use the
unsigned
methods.
Units¶
- return value: meter²
Interpreting negative area values¶
A negative value can mean one of two things:
1. The winding of the polygon is in the clockwise direction (reverse winding). If this is the case, and you know the polygon is smaller than half the area of earth, you can take the absolute value of the reported area to get the correct area.
2. The polygon is larger than half the planet. In this case, the returned area of the polygon is not correct. If you expect to be dealing with very large polygons, please use the unsigned
methods.
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_area_unsigned
method descriptor
¶
geodesic_area_unsigned() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth. Supports very large geometries that cover a significant portion of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Features standard. Using alternative windings will result in incorrect results.
Units¶
- return value: meter²
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_length
method descriptor
¶
geodesic_length() -> ChunkedFloat64Array
Determine the length of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013). As opposed to older methods like Vincenty, this method is accurate to a few nanometers and always converges.
geodesic_perimeter
method descriptor
¶
geodesic_perimeter() -> ChunkedFloat64Array
Determine the perimeter of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
For a polygon this returns the sum of the perimeter of the exterior ring and interior rings.
To get the perimeter of just the exterior ring of a polygon, do polygon.exterior().geodesic_length()
.
Units¶
- return value: meter
Returns:
-
ChunkedFloat64Array
–Array with output values.
is_empty
method descriptor
¶
is_empty() -> BooleanArray
length
method descriptor
¶
length() -> ChunkedFloat64Array
(Euclidean) Calculation of the length of a Line
signed_area
method descriptor
¶
signed_area()
Signed planar area of a geometry array
Returns:
-
–
Chunked array with area values.
simplify
method descriptor
¶
simplify(epsilon: float) -> Self
Simplifies a geometry.
The Ramer–Douglas–Peucker algorithm simplifies a linestring. Polygons are simplified by running the RDP algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology.
Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
simplify_vw
method descriptor
¶
simplify_vw(epsilon: float) -> Self
Returns the simplified representation of a geometry, using the Visvalingam-Whyatt algorithm
See here for a graphical explanation
Polygons are simplified by running the algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology. Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
ChunkedLineStringArray ¶
An immutable chunked array of LineString geometries using GeoArrow's in-memory representation.
area
method descriptor
¶
area() -> ChunkedFloat64Array
Unsigned planar area of a geometry array
Returns:
-
ChunkedFloat64Array
–Chunked array with area values.
center
method descriptor
¶
center() -> ChunkedPointArray
Compute the center of geometries
This first computes the axis-aligned bounding rectangle, then takes the center of that box
Returns:
-
ChunkedPointArray
–Array with center values.
centroid
method descriptor
¶
centroid() -> ChunkedPointArray
Calculation of the centroid.
The centroid is the arithmetic mean position of all points in the shape. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin.
The geometric centroid of a convex object always lies in the object. A non-convex object might have a centroid that is outside the object itself.
Returns:
-
ChunkedPointArray
–Array with centroid values.
chaikin_smoothing
method descriptor
¶
chaikin_smoothing(n_iterations: int) -> Self
Smoothen LineString
, Polygon
, MultiLineString
and MultiPolygon
using Chaikins algorithm.
Each iteration of the smoothing doubles the number of vertices of the geometry, so in some cases it may make sense to apply a simplification afterwards to remove insignificant coordinates.
This implementation preserves the start and end vertices of an open linestring and smoothes the corner between start and end of a closed linestring.
Parameters:
-
n_iterations
(int
) –Number of iterations to use for smoothing.
Returns:
-
Self
–Smoothed geometry array.
chamberlain_duquette_signed_area
method descriptor
¶
chamberlain_duquette_signed_area() -> ChunkedFloat64Array
Calculate the signed approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chamberlain_duquette_unsigned_area
method descriptor
¶
chamberlain_duquette_unsigned_area() -> ChunkedFloat64Array
Calculate the unsigned approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chunks
method descriptor
¶
chunks() -> List[LineStringArray]
Convert to a list of single-chunked arrays.
concatenate
method descriptor
¶
concatenate() -> LineStringArray
Concatenate a chunked array into a contiguous array.
convex_hull
method descriptor
¶
convex_hull() -> ChunkedPolygonArray
Returns the convex hull of a Polygon. The hull is always oriented counter-clockwise.
This implementation uses the QuickHull algorithm, based on Barber, C. Bradford; Dobkin, David P.; Huhdanpaa, Hannu (1 December 1996) Original paper here: www.cs.princeton.edu/~dpd/Papers/BarberDobkinHuhdanpaa.pdf
Returns:
-
ChunkedPolygonArray
–Array with convex hull polygons.
densify
method descriptor
¶
densify(max_distance: float) -> Self
envelope
method descriptor
¶
envelope()
Computes the minimum axis-aligned bounding box that encloses an input geometry
Returns:
-
–
Array with axis-aligned bounding boxes.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self
geodesic_area_signed
method descriptor
¶
geodesic_area_signed() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Feature standard. Alternative windings may result in a negative area. See "Interpreting negative area values" below.
- Polygons are assumed to be smaller than half the size of the earth. If you expect to be dealing
with polygons larger than this, please use the
unsigned
methods.
Units¶
- return value: meter²
Interpreting negative area values¶
A negative value can mean one of two things:
1. The winding of the polygon is in the clockwise direction (reverse winding). If this is the case, and you know the polygon is smaller than half the area of earth, you can take the absolute value of the reported area to get the correct area.
2. The polygon is larger than half the planet. In this case, the returned area of the polygon is not correct. If you expect to be dealing with very large polygons, please use the unsigned
methods.
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_area_unsigned
method descriptor
¶
geodesic_area_unsigned() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth. Supports very large geometries that cover a significant portion of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Features standard. Using alternative windings will result in incorrect results.
Units¶
- return value: meter²
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_length
method descriptor
¶
geodesic_length() -> ChunkedFloat64Array
Determine the length of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013). As opposed to older methods like Vincenty, this method is accurate to a few nanometers and always converges.
geodesic_perimeter
method descriptor
¶
geodesic_perimeter() -> ChunkedFloat64Array
Determine the perimeter of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
For a polygon this returns the sum of the perimeter of the exterior ring and interior rings.
To get the perimeter of just the exterior ring of a polygon, do polygon.exterior().geodesic_length()
.
Units¶
- return value: meter
Returns:
-
ChunkedFloat64Array
–Array with output values.
is_empty
method descriptor
¶
is_empty() -> BooleanArray
length
method descriptor
¶
length() -> ChunkedFloat64Array
(Euclidean) Calculation of the length of a Line
signed_area
method descriptor
¶
signed_area()
Signed planar area of a geometry array
Returns:
-
–
Chunked array with area values.
simplify
method descriptor
¶
simplify(epsilon: float) -> Self
Simplifies a geometry.
The Ramer–Douglas–Peucker algorithm simplifies a linestring. Polygons are simplified by running the RDP algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology.
Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
simplify_vw
method descriptor
¶
simplify_vw(epsilon: float) -> Self
Returns the simplified representation of a geometry, using the Visvalingam-Whyatt algorithm
See here for a graphical explanation
Polygons are simplified by running the algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology. Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
ChunkedPolygonArray ¶
An immutable chunked array of Polygon geometries using GeoArrow's in-memory representation.
area
method descriptor
¶
area() -> ChunkedFloat64Array
Unsigned planar area of a geometry array
Returns:
-
ChunkedFloat64Array
–Chunked array with area values.
center
method descriptor
¶
center() -> ChunkedPointArray
Compute the center of geometries
This first computes the axis-aligned bounding rectangle, then takes the center of that box
Returns:
-
ChunkedPointArray
–Array with center values.
centroid
method descriptor
¶
centroid() -> ChunkedPointArray
Calculation of the centroid.
The centroid is the arithmetic mean position of all points in the shape. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin.
The geometric centroid of a convex object always lies in the object. A non-convex object might have a centroid that is outside the object itself.
Returns:
-
ChunkedPointArray
–Array with centroid values.
chaikin_smoothing
method descriptor
¶
chaikin_smoothing(n_iterations: int) -> Self
Smoothen LineString
, Polygon
, MultiLineString
and MultiPolygon
using Chaikins algorithm.
Each iteration of the smoothing doubles the number of vertices of the geometry, so in some cases it may make sense to apply a simplification afterwards to remove insignificant coordinates.
This implementation preserves the start and end vertices of an open linestring and smoothes the corner between start and end of a closed linestring.
Parameters:
-
n_iterations
(int
) –Number of iterations to use for smoothing.
Returns:
-
Self
–Smoothed geometry array.
chamberlain_duquette_signed_area
method descriptor
¶
chamberlain_duquette_signed_area() -> ChunkedFloat64Array
Calculate the signed approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chamberlain_duquette_unsigned_area
method descriptor
¶
chamberlain_duquette_unsigned_area() -> ChunkedFloat64Array
Calculate the unsigned approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chunks
method descriptor
¶
chunks() -> List[PolygonArray]
Convert to a list of single-chunked arrays.
concatenate
method descriptor
¶
concatenate() -> PolygonArray
Concatenate a chunked array into a contiguous array.
convex_hull
method descriptor
¶
convex_hull() -> ChunkedPolygonArray
Returns the convex hull of a Polygon. The hull is always oriented counter-clockwise.
This implementation uses the QuickHull algorithm, based on Barber, C. Bradford; Dobkin, David P.; Huhdanpaa, Hannu (1 December 1996) Original paper here: www.cs.princeton.edu/~dpd/Papers/BarberDobkinHuhdanpaa.pdf
Returns:
-
ChunkedPolygonArray
–Array with convex hull polygons.
densify
method descriptor
¶
densify(max_distance: float) -> Self
envelope
method descriptor
¶
envelope()
Computes the minimum axis-aligned bounding box that encloses an input geometry
Returns:
-
–
Array with axis-aligned bounding boxes.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self
geodesic_area_signed
method descriptor
¶
geodesic_area_signed() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Feature standard. Alternative windings may result in a negative area. See "Interpreting negative area values" below.
- Polygons are assumed to be smaller than half the size of the earth. If you expect to be dealing
with polygons larger than this, please use the
unsigned
methods.
Units¶
- return value: meter²
Interpreting negative area values¶
A negative value can mean one of two things:
1. The winding of the polygon is in the clockwise direction (reverse winding). If this is the case, and you know the polygon is smaller than half the area of earth, you can take the absolute value of the reported area to get the correct area.
2. The polygon is larger than half the planet. In this case, the returned area of the polygon is not correct. If you expect to be dealing with very large polygons, please use the unsigned
methods.
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_area_unsigned
method descriptor
¶
geodesic_area_unsigned() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth. Supports very large geometries that cover a significant portion of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Features standard. Using alternative windings will result in incorrect results.
Units¶
- return value: meter²
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_perimeter
method descriptor
¶
geodesic_perimeter() -> ChunkedFloat64Array
Determine the perimeter of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
For a polygon this returns the sum of the perimeter of the exterior ring and interior rings.
To get the perimeter of just the exterior ring of a polygon, do polygon.exterior().geodesic_length()
.
Units¶
- return value: meter
Returns:
-
ChunkedFloat64Array
–Array with output values.
is_empty
method descriptor
¶
is_empty() -> BooleanArray
signed_area
method descriptor
¶
signed_area()
Signed planar area of a geometry array
Returns:
-
–
Chunked array with area values.
simplify
method descriptor
¶
simplify(epsilon: float) -> Self
Simplifies a geometry.
The Ramer–Douglas–Peucker algorithm simplifies a linestring. Polygons are simplified by running the RDP algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology.
Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
simplify_vw
method descriptor
¶
simplify_vw(epsilon: float) -> Self
Returns the simplified representation of a geometry, using the Visvalingam-Whyatt algorithm
See here for a graphical explanation
Polygons are simplified by running the algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology. Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
ChunkedMultiPointArray ¶
An immutable chunked array of MultiPoint geometries using GeoArrow's in-memory representation.
area
method descriptor
¶
area() -> ChunkedFloat64Array
Unsigned planar area of a geometry array
Returns:
-
ChunkedFloat64Array
–Chunked array with area values.
center
method descriptor
¶
center() -> ChunkedPointArray
Compute the center of geometries
This first computes the axis-aligned bounding rectangle, then takes the center of that box
Returns:
-
ChunkedPointArray
–Array with center values.
centroid
method descriptor
¶
centroid() -> ChunkedPointArray
Calculation of the centroid.
The centroid is the arithmetic mean position of all points in the shape. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin.
The geometric centroid of a convex object always lies in the object. A non-convex object might have a centroid that is outside the object itself.
Returns:
-
ChunkedPointArray
–Array with centroid values.
chamberlain_duquette_signed_area
method descriptor
¶
chamberlain_duquette_signed_area() -> ChunkedFloat64Array
Calculate the signed approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chamberlain_duquette_unsigned_area
method descriptor
¶
chamberlain_duquette_unsigned_area() -> ChunkedFloat64Array
Calculate the unsigned approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chunks
method descriptor
¶
chunks() -> List[MultiPointArray]
Convert to a list of single-chunked arrays.
concatenate
method descriptor
¶
concatenate() -> MultiPointArray
Concatenate a chunked array into a contiguous array.
convex_hull
method descriptor
¶
convex_hull() -> ChunkedPolygonArray
Returns the convex hull of a Polygon. The hull is always oriented counter-clockwise.
This implementation uses the QuickHull algorithm, based on Barber, C. Bradford; Dobkin, David P.; Huhdanpaa, Hannu (1 December 1996) Original paper here: www.cs.princeton.edu/~dpd/Papers/BarberDobkinHuhdanpaa.pdf
Returns:
-
ChunkedPolygonArray
–Array with convex hull polygons.
envelope
method descriptor
¶
envelope()
Computes the minimum axis-aligned bounding box that encloses an input geometry
Returns:
-
–
Array with axis-aligned bounding boxes.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self
geodesic_area_signed
method descriptor
¶
geodesic_area_signed() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Feature standard. Alternative windings may result in a negative area. See "Interpreting negative area values" below.
- Polygons are assumed to be smaller than half the size of the earth. If you expect to be dealing
with polygons larger than this, please use the
unsigned
methods.
Units¶
- return value: meter²
Interpreting negative area values¶
A negative value can mean one of two things:
1. The winding of the polygon is in the clockwise direction (reverse winding). If this is the case, and you know the polygon is smaller than half the area of earth, you can take the absolute value of the reported area to get the correct area.
2. The polygon is larger than half the planet. In this case, the returned area of the polygon is not correct. If you expect to be dealing with very large polygons, please use the unsigned
methods.
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_area_unsigned
method descriptor
¶
geodesic_area_unsigned() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth. Supports very large geometries that cover a significant portion of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Features standard. Using alternative windings will result in incorrect results.
Units¶
- return value: meter²
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_length
method descriptor
¶
geodesic_length() -> ChunkedFloat64Array
Determine the length of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013). As opposed to older methods like Vincenty, this method is accurate to a few nanometers and always converges.
geodesic_perimeter
method descriptor
¶
geodesic_perimeter() -> ChunkedFloat64Array
Determine the perimeter of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
For a polygon this returns the sum of the perimeter of the exterior ring and interior rings.
To get the perimeter of just the exterior ring of a polygon, do polygon.exterior().geodesic_length()
.
Units¶
- return value: meter
Returns:
-
ChunkedFloat64Array
–Array with output values.
is_empty
method descriptor
¶
is_empty() -> BooleanArray
length
method descriptor
¶
length() -> ChunkedFloat64Array
(Euclidean) Calculation of the length of a Line
signed_area
method descriptor
¶
signed_area()
Signed planar area of a geometry array
Returns:
-
–
Chunked array with area values.
simplify
method descriptor
¶
simplify(epsilon: float) -> Self
Simplifies a geometry.
The Ramer–Douglas–Peucker algorithm simplifies a linestring. Polygons are simplified by running the RDP algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology.
Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
simplify_vw
method descriptor
¶
simplify_vw(epsilon: float) -> Self
Returns the simplified representation of a geometry, using the Visvalingam-Whyatt algorithm
See here for a graphical explanation
Polygons are simplified by running the algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology. Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
ChunkedMultiLineStringArray ¶
An immutable chunked array of MultiLineString geometries using GeoArrow's in-memory representation.
area
method descriptor
¶
area() -> ChunkedFloat64Array
Unsigned planar area of a geometry array
Returns:
-
ChunkedFloat64Array
–Chunked array with area values.
center
method descriptor
¶
center() -> ChunkedPointArray
Compute the center of geometries
This first computes the axis-aligned bounding rectangle, then takes the center of that box
Returns:
-
ChunkedPointArray
–Array with center values.
centroid
method descriptor
¶
centroid() -> ChunkedPointArray
Calculation of the centroid.
The centroid is the arithmetic mean position of all points in the shape. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin.
The geometric centroid of a convex object always lies in the object. A non-convex object might have a centroid that is outside the object itself.
Returns:
-
ChunkedPointArray
–Array with centroid values.
chaikin_smoothing
method descriptor
¶
chaikin_smoothing(n_iterations: int) -> Self
Smoothen LineString
, Polygon
, MultiLineString
and MultiPolygon
using Chaikins algorithm.
Each iteration of the smoothing doubles the number of vertices of the geometry, so in some cases it may make sense to apply a simplification afterwards to remove insignificant coordinates.
This implementation preserves the start and end vertices of an open linestring and smoothes the corner between start and end of a closed linestring.
Parameters:
-
n_iterations
(int
) –Number of iterations to use for smoothing.
Returns:
-
Self
–Smoothed geometry array.
chamberlain_duquette_signed_area
method descriptor
¶
chamberlain_duquette_signed_area() -> ChunkedFloat64Array
Calculate the signed approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chamberlain_duquette_unsigned_area
method descriptor
¶
chamberlain_duquette_unsigned_area() -> ChunkedFloat64Array
Calculate the unsigned approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chunks
method descriptor
¶
chunks() -> List[MultiLineStringArray]
Convert to a list of single-chunked arrays.
concatenate
method descriptor
¶
concatenate() -> MultiLineStringArray
Concatenate a chunked array into a contiguous array.
convex_hull
method descriptor
¶
convex_hull() -> ChunkedPolygonArray
Returns the convex hull of a Polygon. The hull is always oriented counter-clockwise.
This implementation uses the QuickHull algorithm, based on Barber, C. Bradford; Dobkin, David P.; Huhdanpaa, Hannu (1 December 1996) Original paper here: www.cs.princeton.edu/~dpd/Papers/BarberDobkinHuhdanpaa.pdf
Returns:
-
ChunkedPolygonArray
–Array with convex hull polygons.
densify
method descriptor
¶
densify(max_distance: float) -> Self
envelope
method descriptor
¶
envelope()
Computes the minimum axis-aligned bounding box that encloses an input geometry
Returns:
-
–
Array with axis-aligned bounding boxes.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self
geodesic_area_signed
method descriptor
¶
geodesic_area_signed() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Feature standard. Alternative windings may result in a negative area. See "Interpreting negative area values" below.
- Polygons are assumed to be smaller than half the size of the earth. If you expect to be dealing
with polygons larger than this, please use the
unsigned
methods.
Units¶
- return value: meter²
Interpreting negative area values¶
A negative value can mean one of two things:
1. The winding of the polygon is in the clockwise direction (reverse winding). If this is the case, and you know the polygon is smaller than half the area of earth, you can take the absolute value of the reported area to get the correct area.
2. The polygon is larger than half the planet. In this case, the returned area of the polygon is not correct. If you expect to be dealing with very large polygons, please use the unsigned
methods.
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_area_unsigned
method descriptor
¶
geodesic_area_unsigned() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth. Supports very large geometries that cover a significant portion of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Features standard. Using alternative windings will result in incorrect results.
Units¶
- return value: meter²
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_length
method descriptor
¶
geodesic_length() -> ChunkedFloat64Array
Determine the length of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013). As opposed to older methods like Vincenty, this method is accurate to a few nanometers and always converges.
geodesic_perimeter
method descriptor
¶
geodesic_perimeter() -> ChunkedFloat64Array
Determine the perimeter of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
For a polygon this returns the sum of the perimeter of the exterior ring and interior rings.
To get the perimeter of just the exterior ring of a polygon, do polygon.exterior().geodesic_length()
.
Units¶
- return value: meter
Returns:
-
ChunkedFloat64Array
–Array with output values.
is_empty
method descriptor
¶
is_empty() -> BooleanArray
length
method descriptor
¶
length() -> ChunkedFloat64Array
(Euclidean) Calculation of the length of a Line
signed_area
method descriptor
¶
signed_area()
Signed planar area of a geometry array
Returns:
-
–
Chunked array with area values.
simplify
method descriptor
¶
simplify(epsilon: float) -> Self
Simplifies a geometry.
The Ramer–Douglas–Peucker algorithm simplifies a linestring. Polygons are simplified by running the RDP algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology.
Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
simplify_vw
method descriptor
¶
simplify_vw(epsilon: float) -> Self
Returns the simplified representation of a geometry, using the Visvalingam-Whyatt algorithm
See here for a graphical explanation
Polygons are simplified by running the algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology. Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
ChunkedMultiPolygonArray ¶
An immutable chunked array of MultiPolygon geometries using GeoArrow's in-memory representation.
area
method descriptor
¶
area() -> ChunkedFloat64Array
Unsigned planar area of a geometry array
Returns:
-
ChunkedFloat64Array
–Chunked array with area values.
center
method descriptor
¶
center() -> ChunkedPointArray
Compute the center of geometries
This first computes the axis-aligned bounding rectangle, then takes the center of that box
Returns:
-
ChunkedPointArray
–Array with center values.
centroid
method descriptor
¶
centroid() -> ChunkedPointArray
Calculation of the centroid.
The centroid is the arithmetic mean position of all points in the shape. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin.
The geometric centroid of a convex object always lies in the object. A non-convex object might have a centroid that is outside the object itself.
Returns:
-
ChunkedPointArray
–Array with centroid values.
chaikin_smoothing
method descriptor
¶
chaikin_smoothing(n_iterations: int) -> Self
Smoothen LineString
, Polygon
, MultiLineString
and MultiPolygon
using Chaikins algorithm.
Each iteration of the smoothing doubles the number of vertices of the geometry, so in some cases it may make sense to apply a simplification afterwards to remove insignificant coordinates.
This implementation preserves the start and end vertices of an open linestring and smoothes the corner between start and end of a closed linestring.
Parameters:
-
n_iterations
(int
) –Number of iterations to use for smoothing.
Returns:
-
Self
–Smoothed geometry array.
chamberlain_duquette_signed_area
method descriptor
¶
chamberlain_duquette_signed_area() -> ChunkedFloat64Array
Calculate the signed approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chamberlain_duquette_unsigned_area
method descriptor
¶
chamberlain_duquette_unsigned_area() -> ChunkedFloat64Array
Calculate the unsigned approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chunks
method descriptor
¶
chunks() -> List[MultiPolygonArray]
Convert to a list of single-chunked arrays.
concatenate
method descriptor
¶
concatenate() -> MultiPolygonArray
Concatenate a chunked array into a contiguous array.
convex_hull
method descriptor
¶
convex_hull() -> ChunkedPolygonArray
Returns the convex hull of a Polygon. The hull is always oriented counter-clockwise.
This implementation uses the QuickHull algorithm, based on Barber, C. Bradford; Dobkin, David P.; Huhdanpaa, Hannu (1 December 1996) Original paper here: www.cs.princeton.edu/~dpd/Papers/BarberDobkinHuhdanpaa.pdf
Returns:
-
ChunkedPolygonArray
–Array with convex hull polygons.
densify
method descriptor
¶
densify(max_distance: float) -> Self
envelope
method descriptor
¶
envelope()
Computes the minimum axis-aligned bounding box that encloses an input geometry
Returns:
-
–
Array with axis-aligned bounding boxes.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self
geodesic_area_signed
method descriptor
¶
geodesic_area_signed() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Feature standard. Alternative windings may result in a negative area. See "Interpreting negative area values" below.
- Polygons are assumed to be smaller than half the size of the earth. If you expect to be dealing
with polygons larger than this, please use the
unsigned
methods.
Units¶
- return value: meter²
Interpreting negative area values¶
A negative value can mean one of two things:
1. The winding of the polygon is in the clockwise direction (reverse winding). If this is the case, and you know the polygon is smaller than half the area of earth, you can take the absolute value of the reported area to get the correct area.
2. The polygon is larger than half the planet. In this case, the returned area of the polygon is not correct. If you expect to be dealing with very large polygons, please use the unsigned
methods.
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_area_unsigned
method descriptor
¶
geodesic_area_unsigned() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth. Supports very large geometries that cover a significant portion of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Features standard. Using alternative windings will result in incorrect results.
Units¶
- return value: meter²
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_perimeter
method descriptor
¶
geodesic_perimeter() -> ChunkedFloat64Array
Determine the perimeter of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
For a polygon this returns the sum of the perimeter of the exterior ring and interior rings.
To get the perimeter of just the exterior ring of a polygon, do polygon.exterior().geodesic_length()
.
Units¶
- return value: meter
Returns:
-
ChunkedFloat64Array
–Array with output values.
is_empty
method descriptor
¶
is_empty() -> BooleanArray
signed_area
method descriptor
¶
signed_area()
Signed planar area of a geometry array
Returns:
-
–
Chunked array with area values.
simplify
method descriptor
¶
simplify(epsilon: float) -> Self
Simplifies a geometry.
The Ramer–Douglas–Peucker algorithm simplifies a linestring. Polygons are simplified by running the RDP algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology.
Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
simplify_vw
method descriptor
¶
simplify_vw(epsilon: float) -> Self
Returns the simplified representation of a geometry, using the Visvalingam-Whyatt algorithm
See here for a graphical explanation
Polygons are simplified by running the algorithm on all their constituent rings. This may result in invalid Polygons, and has no guarantee of preserving topology. Multi* objects are simplified by simplifying all their constituent geometries individually.
An epsilon less than or equal to zero will return an unaltered version of the geometry.
Parameters:
-
epsilon
(float
) –tolerance for simplification.
Returns:
-
Self
–Simplified geometry array.
ChunkedMixedGeometryArray ¶
An immutable chunked array of Geometry geometries using GeoArrow's in-memory representation.
area
method descriptor
¶
area() -> ChunkedFloat64Array
Unsigned planar area of a geometry array
Returns:
-
ChunkedFloat64Array
–Chunked array with area values.
center
method descriptor
¶
center() -> ChunkedPointArray
Compute the center of geometries
This first computes the axis-aligned bounding rectangle, then takes the center of that box
Returns:
-
ChunkedPointArray
–Array with center values.
centroid
method descriptor
¶
centroid() -> ChunkedPointArray
Calculation of the centroid.
The centroid is the arithmetic mean position of all points in the shape. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin.
The geometric centroid of a convex object always lies in the object. A non-convex object might have a centroid that is outside the object itself.
Returns:
-
ChunkedPointArray
–Array with centroid values.
chamberlain_duquette_signed_area
method descriptor
¶
chamberlain_duquette_signed_area() -> ChunkedFloat64Array
Calculate the signed approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chamberlain_duquette_unsigned_area
method descriptor
¶
chamberlain_duquette_unsigned_area() -> ChunkedFloat64Array
Calculate the unsigned approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chunks
method descriptor
¶
chunks() -> List[MixedGeometryArray]
Convert to a list of single-chunked arrays.
concatenate
method descriptor
¶
concatenate() -> MixedGeometryArray
Concatenate a chunked array into a contiguous array.
convex_hull
method descriptor
¶
convex_hull() -> ChunkedPolygonArray
Returns the convex hull of a Polygon. The hull is always oriented counter-clockwise.
This implementation uses the QuickHull algorithm, based on Barber, C. Bradford; Dobkin, David P.; Huhdanpaa, Hannu (1 December 1996) Original paper here: www.cs.princeton.edu/~dpd/Papers/BarberDobkinHuhdanpaa.pdf
Returns:
-
ChunkedPolygonArray
–Array with convex hull polygons.
envelope
method descriptor
¶
envelope()
Computes the minimum axis-aligned bounding box that encloses an input geometry
Returns:
-
–
Array with axis-aligned bounding boxes.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self
geodesic_area_signed
method descriptor
¶
geodesic_area_signed() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Feature standard. Alternative windings may result in a negative area. See "Interpreting negative area values" below.
- Polygons are assumed to be smaller than half the size of the earth. If you expect to be dealing
with polygons larger than this, please use the
unsigned
methods.
Units¶
- return value: meter²
Interpreting negative area values¶
A negative value can mean one of two things:
1. The winding of the polygon is in the clockwise direction (reverse winding). If this is the case, and you know the polygon is smaller than half the area of earth, you can take the absolute value of the reported area to get the correct area.
2. The polygon is larger than half the planet. In this case, the returned area of the polygon is not correct. If you expect to be dealing with very large polygons, please use the unsigned
methods.
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_area_unsigned
method descriptor
¶
geodesic_area_unsigned() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth. Supports very large geometries that cover a significant portion of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Features standard. Using alternative windings will result in incorrect results.
Units¶
- return value: meter²
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_perimeter
method descriptor
¶
geodesic_perimeter() -> ChunkedFloat64Array
Determine the perimeter of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
For a polygon this returns the sum of the perimeter of the exterior ring and interior rings.
To get the perimeter of just the exterior ring of a polygon, do polygon.exterior().geodesic_length()
.
Units¶
- return value: meter
Returns:
-
ChunkedFloat64Array
–Array with output values.
is_empty
method descriptor
¶
is_empty() -> BooleanArray
signed_area
method descriptor
¶
signed_area()
Signed planar area of a geometry array
Returns:
-
–
Chunked array with area values.
ChunkedGeometryCollectionArray ¶
An immutable chunked array of GeometryCollection geometries using GeoArrow's in-memory representation.
area
method descriptor
¶
area() -> ChunkedFloat64Array
Unsigned planar area of a geometry array
Returns:
-
ChunkedFloat64Array
–Chunked array with area values.
center
method descriptor
¶
center() -> ChunkedPointArray
Compute the center of geometries
This first computes the axis-aligned bounding rectangle, then takes the center of that box
Returns:
-
ChunkedPointArray
–Array with center values.
centroid
method descriptor
¶
centroid() -> ChunkedPointArray
Calculation of the centroid.
The centroid is the arithmetic mean position of all points in the shape. Informally, it is the point at which a cutout of the shape could be perfectly balanced on the tip of a pin.
The geometric centroid of a convex object always lies in the object. A non-convex object might have a centroid that is outside the object itself.
Returns:
-
ChunkedPointArray
–Array with centroid values.
chamberlain_duquette_signed_area
method descriptor
¶
chamberlain_duquette_signed_area() -> ChunkedFloat64Array
Calculate the signed approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chamberlain_duquette_unsigned_area
method descriptor
¶
chamberlain_duquette_unsigned_area() -> ChunkedFloat64Array
Calculate the unsigned approximate geodesic area of a Geometry
.
Returns:
-
ChunkedFloat64Array
–Array with area values.
chunks
method descriptor
¶
chunks() -> List[GeometryCollectionArray]
Convert to a list of single-chunked arrays.
concatenate
method descriptor
¶
concatenate() -> GeometryCollectionArray
Concatenate a chunked array into a contiguous array.
convex_hull
method descriptor
¶
convex_hull() -> ChunkedPolygonArray
Returns the convex hull of a Polygon. The hull is always oriented counter-clockwise.
This implementation uses the QuickHull algorithm, based on Barber, C. Bradford; Dobkin, David P.; Huhdanpaa, Hannu (1 December 1996) Original paper here: www.cs.princeton.edu/~dpd/Papers/BarberDobkinHuhdanpaa.pdf
Returns:
-
ChunkedPolygonArray
–Array with convex hull polygons.
envelope
method descriptor
¶
envelope()
Computes the minimum axis-aligned bounding box that encloses an input geometry
Returns:
-
–
Array with axis-aligned bounding boxes.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self
geodesic_area_signed
method descriptor
¶
geodesic_area_signed() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Feature standard. Alternative windings may result in a negative area. See "Interpreting negative area values" below.
- Polygons are assumed to be smaller than half the size of the earth. If you expect to be dealing
with polygons larger than this, please use the
unsigned
methods.
Units¶
- return value: meter²
Interpreting negative area values¶
A negative value can mean one of two things:
1. The winding of the polygon is in the clockwise direction (reverse winding). If this is the case, and you know the polygon is smaller than half the area of earth, you can take the absolute value of the reported area to get the correct area.
2. The polygon is larger than half the planet. In this case, the returned area of the polygon is not correct. If you expect to be dealing with very large polygons, please use the unsigned
methods.
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_area_unsigned
method descriptor
¶
geodesic_area_unsigned() -> ChunkedFloat64Array
Determine the area of a geometry on an ellipsoidal model of the earth. Supports very large geometries that cover a significant portion of the earth.
This uses the geodesic measurement methods given by Karney (2013).
Assumptions¶
- Polygons are assumed to be wound in a counter-clockwise direction for the exterior ring and a clockwise direction for interior rings. This is the standard winding for geometries that follow the Simple Features standard. Using alternative windings will result in incorrect results.
Units¶
- return value: meter²
Returns:
-
ChunkedFloat64Array
–Array with output values.
geodesic_perimeter
method descriptor
¶
geodesic_perimeter() -> ChunkedFloat64Array
Determine the perimeter of a geometry on an ellipsoidal model of the earth.
This uses the geodesic measurement methods given by Karney (2013).
For a polygon this returns the sum of the perimeter of the exterior ring and interior rings.
To get the perimeter of just the exterior ring of a polygon, do polygon.exterior().geodesic_length()
.
Units¶
- return value: meter
Returns:
-
ChunkedFloat64Array
–Array with output values.
is_empty
method descriptor
¶
is_empty() -> BooleanArray
signed_area
method descriptor
¶
signed_area()
Signed planar area of a geometry array
Returns:
-
–
Chunked array with area values.
ChunkedWKBArray ¶
An immutable chunked array of WKB-encoded geometries using GeoArrow's in-memory representation.
from_arrow_arrays
builtin
¶
from_arrow_arrays(input: Sequence[ArrowArrayExportable]) -> Self
Construct this chunked array from existing Arrow data
This is a temporary workaround for this pyarrow
issue, where it's currently impossible to
read a pyarrow ChunkedArray
directly without adding a direct
dependency on pyarrow.
Parameters:
-
input
(Sequence[ArrowArrayExportable]
) –Arrow arrays to use for constructing this object
Returns:
-
Self
–Self