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.

Function	Syntax
Python	`segments(linestring, num_points=2, step_size=1)`
SQL	`ST_Segments(linestring, num_points, step_size)`

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

Examples

Python

SQL

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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)

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

Version table

Release	Notes
1.0.0	Function introduced

ST_Segments

Examples

Version table

Related topics