Teradata Package for Python Function Reference on VantageCloud Lake - union - Teradata Package for Python - Look here for syntax, methods and examples for the functions included in the Teradata Package for Python.

Teradata® Package for Python Function Reference on VantageCloud Lake

Deployment
VantageCloud
Edition
Lake
Product
Release Number
20.00
Published
March 2024
Language
English (United States)
Last Update
2024-05-30
dita:id
Product Category
DESCRIPTION:
Returns a Geometry value that represents the point set union of two
Geometry values.

PARAMETERS:
geom_column:
Required Argument.
Specifies the other Geometry value.
Types: str, ColumnExpression, GeometryType

SUPPORTED GEOMETRY TYPES:
All Geometry types except geometry collections.
Note:
This method can be called on 3D geometries (those that include Z
coordinates). However, the Z coordinate is ignored in method
calculations. Consequently, any Z coordinates returned by this
method should be ignored. Teradata recommends using the make_2D()
method to strip out the Z coordinates of the return value.

RAISES:

RETURNS:
GeoDataFrame
Notes:
Returns a Geometry type where the representation is one of the
possible set of types in the following table, depending on the
parameter types.
+==============+=====+=====+==============+======+======+=======+=======+
| a u b        | Ø   | Pnt | Line, GeoSeq | Poly | MPnt | MLine | MPoly |
+==============+=====+=====+==============+======+======+=======+=======+
| Ø            | Ø   | R01 | R02          | R03  | R04  | R05   | R06   |
+--------------+-----+-----+--------------+------+------+-------+-------+
| Pnt          | R01 | R20 | R15          | R22  | R04  | R17   | R19   |
+--------------+-----+-----+--------------+------+------+-------+-------+
| Line, GeoSeq | R02 | R15 | R16          | R21  | R15  | R16   | R18   |
+--------------+-----+-----+--------------+------+------+-------+-------+
| Poly         | R03 | R22 | R21          | R23  | R22  | R21   | R23   |
+--------------+-----+-----+--------------+------+------+-------+-------+
| MPnt         | R04 | R04 | R15          | R22  | R04  | R17   | R19   |
+--------------+-----+-----+--------------+------+------+-------+-------+
| MLine        | R05 | R17 | R16          | R21  | R17  | R16   | R18   |
+--------------+-----+-----+--------------+------+------+-------+-------+
| MPoly        | R06 | R19 | R18          | R23  | R19  | R18   | R23   |
+--------------+-----+-----+--------------+------+------+-------+-------+
Where:
Pnt, R09    = ST_Point
Line, R02   = ST_LineString
Poly, R03   = ST_Polygon
MPnt, R04   = ST_MultiPoint
MLine, R05  = ST_MultiLineString
MPoly, R06  = ST_MultiPolygon
GeoSeq      = GeoSequence
R15         = ST_LineString,
ST_GeomCollection of ST_Point and ST_LineString values
R16         = ST_LineString, ST_MultiLineString
R17         = ST_MultiLineString,
ST_GeomCollection of ST_Point and ST_LineString values
R18         = ST_MultiPolygon,
ST_GeomCollection of ST_LineString and ST_Polygon values
R19         = ST_MultiPolygon,
ST_GeomCollection of ST_Point and ST_Polygon values
R20         = ST_Point, ST_MultiPoint
R21         = ST_Polygon,
ST_GeomCollection of ST_LineString and ST_Polygon values
R22         = ST_Polygon,
ST_GeomCollection of ST_Point ST_Polygon values
R23         = ST_Polygon, ST_MultiPolygon
Vantage converts GeoSequence types that are involved in the union()
method to ST_LineString values. Therefore, union() never returns a
GeoSequence type.

EXAMPLES:
from teradataml import Point, LineString, Polygon
# Create a GeoDataFrame.
geodf = GeoDataFrame("sample_shapes")
print(geodf)

# Let's select only few columns from GeoDataFrame.
pols_lines = geodf.select(["skey", "polygons", "linestrings"])[geodf.skey.isin([1001, 1002, 1003])]

# Example 1: Get the point set union of geometries in columns 'polygons' and 'linestrings'.
# Set the geometry property of GeoDataFrame to point to 'linestrings' column.
pols_lines.geometry = pols_lines.linestrings
pols_lines.union(geom_column=pols_lines.polygons)

# Example 2: Get the point set union of geometries in column 'polygons' and
#            a GeometryType object - Polygon.
# Set the geometry property of GeoDataFrame to point to 'polygons' column.
pols_lines.geometry = pols_lines.polygons
# Create an object of Polygon GeometryType.
po1 = Polygon([(0, 0), (0, 20), (20, 20), (20, 0), (0, 0)])
# Pass the Polygon() GeometryType object as input to "geom_column" argument.
pols_lines.union(po1)