Convert linestring to polygon（将线串转换为多边形（Convert linestring to polygon））

Supported in: Batch, Faster, Streaming

Convert a linestring geometry to a polygon geometry. This expression assumes the linestring geometry is closed. If not, the expression will return null.

Expression categories: Geospatial

Declared arguments

• Expression: A valid linestring geometry.
  Expression\

Output type: Geometry

Examples

Example 1: Base case

Argument values:

• Expression: polygon_points

polygon_points	Output
{"type":"LineString","coordinates":[[-77.49,38.01],[-77.47,38.15],[-77.19,38.14],[-77.49,38.01]]}	{"type":"Polygon","coordinates":[[[-77.49,38.01],[-77.47,38.15],[-77.19,38.14],[-77.49,38.01]]]}

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Example 2: Null case

Argument values:

• Expression: polygon_points

polygon_points	Output
null	null
{"type":"LineString","coordinates":[[-77.49,38.01],[-77.19,38.14],[-77.49,38.01]]}	null
{"type":"LineString","coordinates":[[-77.49,38.01],[-77.19,38.14]]}	null
{"type":"LineString","coordinates":[[-77.49,38.01]]}	null
{"type":"Polygon","coordinates":[[[-77.49,38.01],[-77.47,38.15],[-77.19,38.14],[-77.49,38.01]]]}	null

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中文翻译

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将线串转换为多边形（Convert linestring to polygon）

支持：批处理（Batch）、快速处理（Faster）、流处理（Streaming）

将线串几何图形转换为多边形几何图形。此表达式假定线串几何图形是闭合的。若非闭合，表达式将返回空值。

表达式类别： 地理空间（Geospatial）

声明的参数

• 表达式（Expression）： 一个有效的线串几何图形。
  表达式\

输出类型： Geometry

示例

示例 1：基本情况

参数值：

• 表达式： polygon_points

polygon_points	输出
{"type":"LineString","coordinates":[[-77.49,38.01],[-77.47,38.15],[-77.19,38.14],[-77.49,38.01]]}	{"type":"Polygon","coordinates":[[[-77.49,38.01],[-77.47,38.15],[-77.19,38.14],[-77.49,38.01]]]}

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示例 2：空值情况

参数值：

• 表达式： polygon_points

polygon_points	输出
null	null
{"type":"LineString","coordinates":[[-77.49,38.01],[-77.19,38.14],[-77.49,38.01]]}	null
{"type":"LineString","coordinates":[[-77.49,38.01],[-77.19,38.14]]}	null
{"type":"LineString","coordinates":[[-77.49,38.01]]}	null
{"type":"Polygon","coordinates":[[[-77.49,38.01],[-77.47,38.15],[-77.19,38.14],[-77.49,38.01]]]}	null

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