ST_Segments

ST_Segments takes a linestring column and returns an array column. The function creates an array of linestrings by splitting the input linestring at a certain number of vertices using a moving window. By default the function will create segments with two points and the moving window will move one point at a time (step size of 1). You can optionally include a larger number of points in each linestring by specifying a numeric value greater than 2. You can also increase the step size by setting it to a value greater than 1. Setting the step size to one less than the number of points will always result in segments that touch but do not overlap.

For more details, go to the GeoAnalytics Engine API reference for segments.

Examples

1
2
3
4
5
6

from geoanalytics.sql import functions as ST, Linestring

df = spark.createDataFrame([(Linestring([[[0, 0], [1, 0], [2, 0], [3, 0], [4, 0]]]),)],["linestring"])

df.select(ST.segments("linestring", 3, 2).alias("segments")).show(truncate=False)

1
2
3
4
5
+------------------------------------------------------------------+
|segments                                                          |
+------------------------------------------------------------------+
|[{"paths":[[[0,0],[1,0],[2,0]]]}, {"paths":[[[2,0],[3,0],[4,0]]]}]|
+------------------------------------------------------------------+

Version table

Related topics

• SQL functions
• Data sources
• Coordinate systems and transformations