Signature
Parameters
float
required
Finite, non-negative scalar. A vertex is eligible when the area
of its triangle with its two neighbours is at most
tolerance ** 2. Tolerance has the units of the coordinates;
it is not a bound on displacement. Zero can remove collinear
vertices. Per-row tolerances are not supported.bool
default:"True"
Whether the exterior boundary of the coverage can change. If
False, simplify only edges shared by two rings.
Returns
GeoSeries
Simplified polygons with the original index levels, CRS and
embedded SRIDs. Missing and empty polygon rows are preserved.
Requires Spark Classic and a checkpoint directory configured with
spark.sparkContext.setCheckpointDir(path). On a cluster, the path
must use storage accessible to all executors, such as HDFS. Local
filesystem paths are appropriate only for local Spark execution.
Intermediate checkpoints are released after their successors are
materialized. The final checkpoint must remain available while the
result or any derived DataFrame is in use. Its files follow Spark’s
checkpoint cleanup policy; this method does not delete the configured
directory or require a public close() call.Input must be a valid, finite, edge-matched 2D Polygon/MultiPolygon
coverage. Non-polygonal values, Z/M coordinates, invalid polygons and
repeated vertices within a ring (apart from closure) are rejected.
Empty interior rings are also rejected; empty polygons and empty
MultiPolygon members are preserved.
Full coverage validity is a precondition, not checked by this method;
use is_valid_coverage separately when needed.The conservative algorithm uses current-segment safety checks and
disjoint edit regions, with at most one vertex removed per ring per
round. It can retain more vertices than GeoPandas/GEOS and never
deletes rings, holes or polygon parts. Results are not guaranteed to
match GeoPandas/GEOS vertex selection.Geometry rows stay distributed, but reconstruction builds arrays per
ring and input geometry. Inputs above 100,000 coordinates per geometry
are rejected. This is an admission limit, not a memory guarantee:
long rings can exhaust executor memory even below that limit. Dense
spatial matches and many synchronization rounds can also be costly.simplify: simplify each geometry independentlyis_valid_coverage: check edge matching and coverage validity