geos_buffer_multi_point

Geometric functions > geos_buffer_multi_point

syntax

• geos_buffer_multi_point(arc_data_item, buffer_distance, nrPointsInCircle)

description

geos_buffer_multi_point(arc_data_item, buffer_distance, nrPointsInCircle) creates a buffer polygon around each coordinate of the arc_data_item. The result is a polygon data item with the same domain as the arc_data_item.

The buffer_distance is a Float64 value that specifies the radius of the buffer in the units of the coordinate system of the arc_data_item.

The nrPointsInCircle is a UInt8 value that specifies the number of points used to approximate the circle per source point. A higher value results in a smoother buffer but increases computation time. The minimum value is 3.

The geos_ prefix of the function name indicates that the implementation of the operator uses geos.

applies to

• attribute arc_data_item with a point value type and arc or polygon composition
• parameter buffer_distance with a Float64 value type
• parameter nrPointsInCircle with a UInt8 value type

conditions

1. buffer_distance must be a positive value.
2. nrPointsInCircle must be at least 3.

since version

7.202

example

attribute<fpoint> buffer_geometry (road) := geos_buffer_multi_point(road/geometry, 50.0, 8b);

see also

• geos_buffer_point
• geos_buffer_linestring
• geos_buffer_multi_polygon
• bg_buffer_multi_point

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