union2union2Union2Union2 (Operator)

Name

union2union2Union2Union2 — Return the union of two regions.

Signature

union2(Region1, Region2 : RegionUnion : : )

Description

union2union2Union2Union2Union2 computes the union of the region in Region1Region1Region1Region1region1 with all regions in Region2Region2Region2Region2region2. Internally, all regions of Region2Region2Region2Region2region2 are united to a single region before the individual regions of Region1Region1Region1Region1region1 are united with the already united region. This means that union2union2Union2Union2Union2 is not commutative!

Execution Information

Multithreading type: reentrant (runs in parallel with non-exclusive operators).
Multithreading scope: global (may be called from any thread).
Processed without parallelization.

Parameters

Region1Region1Region1Region1region1 (input_object) region(-array) → object

Region for which the union with all regions in Region2 is to be computed.

Region2Region2Region2Region2region2 (input_object) region(-array) → object

Regions which should be added to Region1.

RegionUnionRegionUnionRegionUnionRegionUnionregionUnion (output_object) region(-array) → object

Resulting regions.

Number of elements: RegionUnion == Region1

Complexity

Let F be the sum of all areas of the input regions. Then the runtime complexity is O(log(sqrt(F)) * sqrt(F)).

Result

union2union2Union2Union2Union2 always returns 2 (H_MSG_TRUE). The behavior in case of empty input (no regions given) can be set via set_system('no_object_result',<Result>)set_system("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>)SetSystem("no_object_result",<Result>) and the behavior in case of an empty input region via set_system('empty_region_result',<Result>)set_system("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>)SetSystem("empty_region_result",<Result>). If necessary, an exception is raised.

Possible Predecessors

thresholdthresholdThresholdThresholdThreshold, connectionconnectionConnectionConnectionConnection, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowing, pouringpouringPouringPouringPouring

Possible Successors

select_shapeselect_shapeSelectShapeSelectShapeSelectShape, disp_regiondisp_regionDispRegionDispRegionDispRegion

Alternatives

union1union1Union1Union1Union1

See also

intersectionintersectionIntersectionIntersectionIntersection, complementcomplementComplementComplementComplement

Module

Foundation