select_region_spatialT_select_region_spatialSelectRegionSpatialSelectRegionSpatial (Operator)

Name

select_region_spatialT_select_region_spatialSelectRegionSpatialSelectRegionSpatial — Pose relation of regions.

Signature

Description

The operator select_region_spatialselect_region_spatialSelectRegionSpatialSelectRegionSpatialSelectRegionSpatial chooses the regions from Regions2Regions2Regions2Regions2regions2 which are sufficient for the neighboring relation DirectionDirectionDirectionDirectiondirection. The regions to be examined have to be passed in Regions1Regions1Regions1Regions1regions1 or Regions2Regions2Regions2Regions2regions2, respectively. Regions1Regions1Regions1Regions1regions1 can have three different states:

• Regions1Regions1Regions1Regions1regions1 is empty:
  In this case all regions in Regions2Regions2Regions2Regions2regions2 are permutatively checked for neighborhood.

• Regions1Regions1Regions1Regions1regions1 consists of one region:
  The regions of Regions1Regions1Regions1Regions1regions1 are compared to all regions in Regions2Regions2Regions2Regions2regions2.

• Regions1Regions1Regions1Regions1regions1 consists of the same number of regions as Regions2Regions2Regions2Regions2regions2:
  The regions at the n-th position in Regions1Regions1Regions1Regions1regions1 and Regions2Regions2Regions2Regions2regions2 are each checked for a neighboring relation.

Possible values for DirectionDirectionDirectionDirectiondirection are:

'left':

Regions2Regions2Regions2Regions2regions2 is left of Regions1Regions1Regions1Regions1regions1

'right':

Regions2Regions2Regions2Regions2regions2 is right of Regions1Regions1Regions1Regions1regions1

'above':

Regions2Regions2Regions2Regions2regions2 is above Regions1Regions1Regions1Regions1regions1

'below':

Regions2Regions2Regions2Regions2regions2 is below Regions1Regions1Regions1Regions1regions1

The operator select_region_spatialselect_region_spatialSelectRegionSpatialSelectRegionSpatialSelectRegionSpatial calculates the centers of the regions to be compared and decides according to the angle between the center straight lines and the x axis whether the direction relation is fulfilled. The relation is fulfilled within the area of -45 degree to +45 degree around the coordinate axes. Thus, the direction relation can be understood in such a way that the center of the second region must be located left (or right, above, below) of the center of the first region. The indices of the regions fulfilling the direction relation are located at the n-th position in RegionIndex1RegionIndex1RegionIndex1RegionIndex1regionIndex1 and RegionIndex2RegionIndex2RegionIndex2RegionIndex2regionIndex2, i.e., the region with the index RegionIndex2RegionIndex2RegionIndex2RegionIndex2regionIndex2[n] has the indicated relation with the region with the index RegionIndex1RegionIndex1RegionIndex1RegionIndex1regionIndex1[n]. Access to regions via the index can be obtained via the operator copy_objcopy_objCopyObjCopyObjCopyObj.

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

Result

The operator select_region_spatialselect_region_spatialSelectRegionSpatialSelectRegionSpatialSelectRegionSpatial returns the value 2 (H_MSG_TRUE) if Regions2Regions2Regions2Regions2regions2 is not empty. The behavior in case of empty parameter Regions2Regions2Regions2Regions2regions2 (no input regions available) is set via the operator 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>). The behavior in case of empty region (the region is the empty set) is set 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, regiongrowingregiongrowingRegiongrowingRegiongrowingRegiongrowing, connectionconnectionConnectionConnectionConnection

Alternatives

area_centerarea_centerAreaCenterAreaCenterAreaCenter, intersectionintersectionIntersectionIntersectionIntersection

See also

spatial_relationspatial_relationSpatialRelationSpatialRelationSpatialRelation, find_neighborsfind_neighborsFindNeighborsFindNeighborsFindNeighbors, copy_objcopy_objCopyObjCopyObjCopyObj, obj_to_integerobj_to_integerObjToIntegerObjToIntegerObjToInteger

Module

Foundation