Polygon processing example
configuration-examples Polygon processing
This script explores different polygon processing operations, using different shapes like circles, squares and triangles.
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concepts
- configuring shapes like circles, squares and triangles
- polygon operations
- reprojections
functions
- union_polygon-(dissolve)
- partitioned_union_polygon-(dissolve-by-attribute)
- mul-(polygon-intersection)
- sub-(difference)
- polygon_connectivity
- points2sequence
- polygon-inflated
- polygon-deflated
- overlay_polygon - domain unit with the intersecting part of each polygon
- split_polygon - domain unit with all single polygons
- split_partitioned_union_polygon - combination of split_polygon and partitioned_union_polygon
- union_polygon-(dissolve) - remove lines of adjacent polygons
- partitioned_union_polygon-(dissolve-by-attribute) - remove lines of adjacent polygons, grouped by a relation
Test:
- bg_buffer_linestring
- bg_buffer_multi_point
- bg_buffer_multi_polygon
- bg_buffer_point
- [[bg_buffer__multi_polygon]]
- bg_intersect
- bg_simplify_linestring
- bg_simplify_multi_polygon
- bg_simplify_polygon
- bg_outer_multi_polygon
- overlay
- overlay_polygon
- overlay32
- overlay64
- [[partitioned_union_polygon]]
- [[partitioned_union_polygon_d16D]]
- [[partitioned_union_polygon_d16D_deflated]]
- [[partitioned_union_polygon_d16D_filtered]]
- [[partitioned_union_polygon_d16D_inflated]]
- [[partitioned_union_polygon_deflated]]
- [[partitioned_union_polygon_deflated_deflated]]
- [[partitioned_union_polygon_deflated_filtered]]
- [[partitioned_union_polygon_deflated_inflated]]
- [[partitioned_union_polygon_filtered]]
- [[partitioned_union_polygon_inflated]]
- points2polygon
- [[polygon_filtered]]
- split_partitioned_union_polygon
- split_partitioned_union_polygon_deflated
- split_partitioned_union_polygon_filtered
- split_polygon
- [[split_polygon_deflated]]
- split_partitioned_union_polygon
- [[union_polygon]]
- [[union_polygon_filtered]]
What are these?
- [[greedy_alloc]]
- [[greedy_alloc_16]]
- potential
- [[potentialIpps64]]
- [[potentialPacked]]
- [[potentialRaw64]]
- [[potentialRawPacked]]
- [[potentialSlow]]
Base operators:
- polygon
- union_polygon
- partitioned_union_polygon
- split_polygon
- split_union_polygon
- split_partitioned_union_polygon
suffixes: 2x
- ‘no suffix’
- _filtered = filter results on area. filter parameter, e.g., 3[meter] keeps all polygons with an area larger than 3[meter].
- _inflated = inflate with parameter value, e.g., 3[meter] which place an edge 3[meter] perpendicular to the original. This could result in very thin, pointy corners. To counteract this, use the iXy or dXy variants.
- _deflated
- _i4HV = inflate with a 4-point square-shape
- _i4D = inflate with a 4-point diamond-shape
- _i8D
- _i16D
- _iXHV
- _iXD
- _d4HV
- _d4D
- _d8D
- _d16D
- _dXHV
- _dXD
Suffix meaning: _[a][X][y]
- a = i (inflate) or d (deflate)
- X = 4, 8 16, X (degree of rounding)
- y = kernel shape = D (diagonal, diamond-shaped) or HV (horizontal and vertical, square-shaped)
There are different ways of inflating polygons related to how angles are treated, i.e., differences in how the angles are rounded off. X represents a user-defined degree of roundness, which can be 4, 8, 16 or X. The suffix ‘d’ or ‘hv’ is used for the diagonal (diamond-shaped) or horizontal-vertical (square-shaped) kernel. For these inflations, the Minkowski sum method is used.