st_pointn

Important

This feature is in Public Preview.

Returns the 1-based n-th point of the input linestring, or None if it doesn't exist.

For the corresponding Databricks SQL function, see st_pointn function.

Syntax

from pyspark.databricks.sql import functions as dbf

dbf.st_pointn(col1=<col1>, col2=<col2>)

Parameters

Parameter	Type	Description
col1	pyspark.sql.Column or str	A Geography or Geometry value representing a linestring.
col2	pyspark.sql.Column or int	A 1-based position in the linestring indicating the point that should be returned.

Examples

from pyspark.databricks.sql import functions as dbf
df = spark.createDataFrame([('LINESTRING(1 2,3 4,5 6)',)], ['wkt'])
df.select(dbf.st_asewkt(dbf.st_pointn(dbf.st_geogfromtext('wkt'), 3)).alias('result')).collect()

[Row(result='SRID=4326;POINT(5 6)')]

from pyspark.databricks.sql import functions as dbf
df = spark.createDataFrame([('LINESTRING ZM (1 2 3 4,5 6 7 8)',)], ['wkt'])
df.select(dbf.st_asewkt(dbf.st_pointn(dbf.st_geomfromtext('wkt', 4326), -2)).alias('result')).collect()

[Row(result='SRID=4326;POINT ZM (1 2 3 4)')]