Geometric functions

Geometric functions calculate with geometries (coordinates) of points, arcs or polygons

point

point_xy - make a point attribute based on an X and Y attribute
point_yx - make a point attribute based on an Y and X attribute
point_isnearby - compare if two points are (almost) the same location
pointrow - get the row numbers of a point attribute
pointcol - get the column numbers of a point attribute
get_x - get the x coordinate of a point attribute
get_y - get the y coordinate of a point attribute
dist(ance) - calculate the distance between two point sets
sq(ua)r(e)dist(ance) - calculate the square distance between two arrays of points
bg_buffer_point - creates a buffer polygon for each point in a pointset
point - DEPRECIATED: make a point attribute based on an X and Y attribute

area - calculates the surface of each polygon
centroid
centroid_or_mid - the centroid if it is located within a polygon or else a mid-point of a polygon.
poly2grid - a grid representation of polygons
poly2grid_untiled - a grid representation of polygons
lower_bound - the lowest X and Y values of the points in each polygon
upper_bound - the highest X and Y values of the points in each polygon
center_bound - the center X and Y values of the points in each polygon
points2polygon
sub-(difference) - a cutout of a polygon in another polygon, where both domains match or one is void
mul-(polygon-intersection) - the overlap of two arrays of polygons, where both domains match or one is void
add-(union) - the element-by-element union of two polygons, where both domains match or one is void
box_connectivity - domain unit with the connected polygons based on their bounding box (this should be less precise but faster than polygon_connectivity)

bp_split_polygon (or old syntax split_polygon) - domain unit with all single polygons
bp_split_union_polygon (or old syntax split_partitioned_union_polygon) - combination of split_polygon and partitioned_union_polygon
polygon-inflated - increases each polygon
polygon-deflated - decreases each polygon
polygon_connectivity - domain unit with the connected polygons
bp_union_polygon (or old syntax union_polygon-(dissolve) or partitioned_union_polygon-(dissolve-by-attribute)) - *remove lines of adjacent polygons, optionally grouped by a relation**
bp_overlay_polygon (or old syntax overlay_polygon
[[bp_polygon]]

Several boost polygon functions can be combined in a single operator; for the full list of those combinations, see here

bg_simplify_single_polygon - simplify the geometry of a single polygon, see for documentation: bg_simplify_multi_polygon
bg_simplify_multi_polygon - simplify the geometry of a multi polygon
bg_buffer_single_polygon - creates a buffer polygon for each single polygon; see for documentation: bg_buffer_multi_polygon
bg_buffer_multi_polygon - creates a buffer polygon for each multi polygon
bg_outer_single_polygon - selects only the outer ring of a single polygon; see for documentation: bg_outer_multi_polygon
bg_outer_multi_polygon - selects only the outer ring of a multi polygon
bg_intersect - intersect the polygon arguments, where both domains match, or one is void
bg_difference - takes the difference of the polygon arguments, where both domains match or one is void
bg_union - union the polygon arguments, where both domains match or one is void
bg_xor - xor the polygon arguments, where both domains match or one is void
bg_overlay_polygon - see overlay_polygon
bg_simplify_polygon - DEPRICIATED simplify the geometry of a polygon
bg_split_polygon
bg_union_polygon
bg_split_union_polygon
[[bg_polygon]]

For examples, see here.

dyna_point / dyna_point_with_ends - configures a point set for an arc on an equal distance
dyna_segment / dyna_segments_with_ends - configures a segment set for an arc on an equal distance

point_in_polygon - index number of the polygon in which a point is located
point_in_ranked_polygon - index number of the polygon in which a point is located, using a ranking in case a polygon is located in multiple polygons
point_in_all_polygons - relation between index numbers of the polygons in which points are located
sequence2points - all vertices of each arc/polygon as separate points
points2sequence - constructs arc/polygon from vertices

arc_length
mls_length
split_multi_linestring
arc2segm - divides an arc/polygon data item into segments
bg_simplify_linestring - simplifies the geometry of an arc
bg_buffer_linestring - creates a buffer polygon for each arc
bg_buffer_multi_point- creates a buffer polygon for each coordinate of the arc/polygon