intersection — Calculate the intersection of two regions.
intersection(Region1, Region2 : RegionIntersection : : )
intersection calculates the intersection of the regions in Region1 with the regions in Region2. Each region in Region1 is intersected with all regions in Region2. That is, internally all regions of Region2 are united to a single region before the individual regions of Region1 are intersected with the united region. The order of regions in RegionIntersection is identical to the order of regions in Region1.
Empty input regions are permitted. Because empty result regions are possible, the system flag 'store_empty_region' should be set appropriately.
Regions to be intersected with all regions in Region2.
Regions with which Region1 is intersected.
Result of the intersection.
Number of elements: RegionIntersection <= Region1
Let N be the number of regions in Region1, be their average area, and be the total area of all regions in Region2. Then the runtime complexity is .
intersection 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>) and the behavior in case of an empty input region via set_system('empty_region_result',<Result>). If necessary, an exception is raised.
threshold, connection, regiongrowing, pouring
union1, union2, complement