Bg_buffer_multi_point
geometric-functions bg_buffer_multi_point
syntax
- bg_buffer_multi_point(arc/polygon_data_item, size, nr_angles)
definition
bg_buffer_multi_point(arc/polygon_data_item, size, nr_angles) results in a multi polygon data-item with buffer circles around each coordinate in the arc/polygon_data_item. The resulting data item has the same domain-unit as the arc/polygon_data_item.
The size arguments indicate the buffer circle size.
The nr_angles arguments indicate how many angles are used to make the buffer circles. More angles result in smoother circles but also in more data.
The bg_ prefix of the function name indicates that the implementation of the operator uses boost geometry library, more specifically, the buffer function.
applies to
- attribute arc/polygon_data_item with a point value-type and composition type arc or polygon
- data-item size with a float64 value type (until version 14.11.2 argument size could only be a parameter)
- data-item nr_angles with a uint8 value type (until version 14.11.2 argument nr_angles could only be a parameter)
since version
7.413
example
attribute<fpoint> buffer_circles (polygon, district) := bg_buffer_multi_point(district/geometry, 10.0, 16b);
more examples of buffer functions can be found here: Buffer processing