Symmetric Difference

Draft: written, not yet checked by a person Operation · symmetric-difference

The parts of two layers that are covered by one layer but not both.

Pitfall. Functions that work per pair of geometries need each layer unioned first to compare whole layers.

About this operation
Also called	Symmetrical Difference, XOR overlay, exclusive or
Group	`vector/overlay`
Checks	`crs.agreement, geometry.valid, extent.plausible`
Pitfalls	1 listed above
Columbus tool	Not stated
Notes	Not stated
Status	active
Broader	Not stated
Narrower	Not stated
Related	`difference` `union-overlay` `intersect`

Parameters

Not stated

Direction	Name	Type	Geometry	Note
Input	`a`	vector	polygon	Not stated
Input	`b`	vector	polygon	Not stated
Output	`output`	vector	polygon	Not stated

Engine	Tool	Parameters	Differences
`apache-sedona`	`sedona.sql.ST_SymDifference`	`a` → `a` `b` → `b`	Per pair of geometries: union each layer first to compare whole layers. A Spark SQL function: arguments are columns or column names, run over a Spark DataFrame.
`gdal`	`gdal vector layer-algebra`	`a` → `input` `b` → `method` `output` → `output`	None noted Preset: `{"operation":"sym-difference"}`
`geopandas`	`geopandas.GeoSeries.symmetric_difference`	`b` → `other`	Element-wise against another GeoSeries (aligned on the index) or one geometry; geopandas.overlay(how='symmetric_difference') works on whole layers.
`grass`	`v.overlay`	`a` → `ainput` `b` → `binput` `output` → `output`	The b input must be areas. Preset: `{"operator":"xor"}`
`postgis`	`st_symdifference`	`a` → `geom1` `b` → `geom2`	Per pair of geometries: union each layer first to compare whole layers.
`qgis`	`native:symmetricaldifference`	`a` → `INPUT` `b` → `OVERLAY` `output` → `OUTPUT`	None noted
`shapely`	`shapely.symmetric_difference`	`a` → `a` `b` → `b`	Per pair of geometries: union each layer first to compare whole layers.
`whiteboxtools`	`SymmetricalDifference`	`a` → `input` `b` → `overlay` `output` → `output`	None noted