snowflake.snowpark.functions.st_pointn

snowflake.snowpark.functions.st_pointn(geography_or_geometry_expression: Union[snowflake.snowpark.column.Column, str], index: Union[snowflake.snowpark.column.Column, str]) → Column[source]

Returns the Nth point in a LINESTRING. Points are indexed starting from 1. Negative values are counted backwards from the end of the LINESTRING, where -1 is the last point.

Parameters:

  • geography_or_geometry_expression (ColumnOrName) – LINESTRING values in GEOGRAPHY or GEOMETRY format

  • index (ColumnOrName) – The 1-based index of the point to return. Negative values count from the end

Returns:

The Nth point as a POINT object

Return type:

Column

Examples::
>>> from snowflake.snowpark.functions import to_geography, to_geometry, lit
>>> df = session.create_dataframe([["LINESTRING(1 1, 2 2, 3 3, 4 4)"]], schema=["linestring"])
>>> df.select(st_pointn(to_geography(df["linestring"]), lit(2)).alias("point")).collect()
[Row(POINT='{\n  "coordinates": [\n    2.000000000000000e+00,\n    2.000000000000000e+00\n  ],\n  "type": "Point"\n}')]
>>> df.select(st_pointn(to_geometry(df["linestring"]), lit(-2)).alias("point")).collect()
[Row(POINT='{\n  "coordinates": [\n    3.000000000000000e+00,\n    3.000000000000000e+00\n  ],\n  "type": "Point"\n}')]