Interpolate geo point along linestring（沿线串插值地理点）¶

Supported in: Batch, Streaming

Returns a point interpolated along a line. Implementation interprets lines as the shortest path, using a spherical approximation of the globe.

Expression categories: Geospatial

Declared arguments¶

Fraction: Fraction of the total length of the linestring at which to pull a geo point, starting from the beginning of the linestring. Must be a float between 0 and 1.
Expression\
Linestring: Linestring along which to interpolate a geo point.
Expression\

Output type: GeoPoint

Examples¶

Example 1: Base case¶

Argument values:

Fraction: fraction
Linestring: linestring

linestring	fraction	Output
{"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}	0.5	{ latitude: 1.0352686301676643, longitude: 15.004677545504547, }
{"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}	0.8	{ latitude: 2.8256098405656185, longitude: 45.99752305664789, }
{"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}	0.2	{ latitude: 8.363732883448177, longitude: 54.073497456494955, }

Example 2: Base case¶

Argument values:

Fraction: fraction
Linestring: linestring

linestring	fraction	Output
{"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}	0.5	{ latitude: 1.0352686301676643, longitude: 15.004677545504547, }
{"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}	0.8	{ latitude: 2.8256098405656185, longitude: 45.99752305664789, }
{"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}	0.2	{ latitude: 8.363732883448177, longitude: 54.073497456494955, }

Example 3: Base case¶

Argument values:

Fraction: fraction
Linestring: linestring

linestring	fraction	Output
{"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}	0.5	{ latitude: 1.0352686301676643, longitude: 15.004677545504547, }
{"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}	0.8	{ latitude: 2.825609851378893, longitude: 45.99752329517703, }
{"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}	0.2	{ latitude: 8.363732872387065, longitude: 54.0734975914614, }

Example 4: Null case¶

Argument values:

Fraction: fraction
Linestring: linestring

linestring	fraction	Output
{"type":"LineString","coordinates":[[10.0,4.0],[75.0,0.0]]}	null	null
{"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}	-0.5	null
{"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}	1.6	null
{"type":"MultiLineString","coordinates":[[[100.0,0.0]], [[102.0,2.0]]]}	0.4	null
{"type":"GeometryCollection","geometries":{"type":"LineString","coordinates":[[10.0,4.0]]}}	0.5	null
null	1.0	null

Example 5: Edge case¶

Description: Fraction values of 0 return a GeoPoint at the start point and fraction values of 1 return a GeoPoint at the end point. There exist floating point errors but should be precise enough for almost all use cases.

Argument values:

Fraction: fraction
Linestring: linestring

linestring	fraction	Output
{"type":"LineString","coordinates":[[10.0,4.0],[75.0,0.0]]}	0.0	{ latitude: 4.0, longitude: 9.999999999999998, }
{"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}	1.0	{ latitude: 0.0, longitude: 35.0, }
{"type":"LineString","coordinates":[[10.0,8.4],[35.0,0.0],[163.0,67.9]]}	1.0	{ latitude: 67.90000000000002, longitude: 163.0, }
{"type":"LineString","coordinates":[[10.0,8.4],[35.0,0.0],[163.0,67.9]]}	0.0	{ latitude: 8.400000000000002, longitude: 9.999999999999998, }

中文翻译¶

沿线串插值地理点¶

支持：批处理（Batch）、流处理（Streaming）

返回沿一条线插值得到的点。该实现将线解释为最短路径，使用地球的球面近似模型。

表达式类别： 地理空间（Geospatial）

声明的参数¶

分数（Fraction）： 从线串起点开始，提取地理点位置占线串总长度的比例。必须是介于0和1之间的浮点数。
表达式\
线串（Linestring）： 用于插值地理点的线串。
表达式\

输出类型： GeoPoint

示例¶

示例1：基本情况¶

参数值：

分数： fraction
线串： linestring

linestring	fraction	输出
{"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}	0.5	{ latitude: 1.0352686301676643, longitude: 15.004677545504547, }
{"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}	0.8	{ latitude: 2.8256098405656185, longitude: 45.99752305664789, }
{"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}	0.2	{ latitude: 8.363732883448177, longitude: 54.073497456494955, }

示例2：基本情况¶

参数值：

分数： fraction
线串： linestring

linestring	fraction	输出
{"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}	0.5	{ latitude: 1.0352686301676643, longitude: 15.004677545504547, }
{"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}	0.8	{ latitude: 2.8256098405656185, longitude: 45.99752305664789, }
{"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}	0.2	{ latitude: 8.363732883448177, longitude: 54.073497456494955, }

示例3：基本情况¶

参数值：

分数： fraction
线串： linestring

linestring	fraction	输出
{"type":"LineString","coordinates":[[0.0,2.0],[30.0,0.0]]}	0.5	{ latitude: 1.0352686301676643, longitude: 15.004677545504547, }
{"type":"LineString","coordinates":[[30.0,2.0],[50.0,3.0]]}	0.8	{ latitude: 2.825609851378893, longitude: 45.99752329517703, }
{"type":"LineString","coordinates":[[45.0,9.0],[90.0,4.0]]}	0.2	{ latitude: 8.363732872387065, longitude: 54.0734975914614, }

示例4：空值情况¶

参数值：

分数： fraction
线串： linestring

linestring	fraction	输出
{"type":"LineString","coordinates":[[10.0,4.0],[75.0,0.0]]}	null	null
{"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}	-0.5	null
{"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}	1.6	null
{"type":"MultiLineString","coordinates":[[[100.0,0.0]], [[102.0,2.0]]]}	0.4	null
{"type":"GeometryCollection","geometries":{"type":"LineString","coordinates":[[10.0,4.0]]}}	0.5	null
null	1.0	null

示例5：边界情况¶

描述： 分数值为0时返回起点处的GeoPoint，分数值为1时返回终点处的GeoPoint。存在浮点误差，但对于绝大多数使用场景而言精度足够。

参数值：

分数： fraction
线串： linestring

linestring	fraction	输出
{"type":"LineString","coordinates":[[10.0,4.0],[75.0,0.0]]}	0.0	{ latitude: 4.0, longitude: 9.999999999999998, }
{"type":"LineString","coordinates":[[10.0,8.0],[35.0,0.0]]}	1.0	{ latitude: 0.0, longitude: 35.0, }
{"type":"LineString","coordinates":[[10.0,8.4],[35.0,0.0],[163.0,67.9]]}	1.0	{ latitude: 67.90000000000002, longitude: 163.0, }
{"type":"LineString","coordinates":[[10.0,8.4],[35.0,0.0],[163.0,67.9]]}	0.0	{ latitude: 8.400000000000002, longitude: 9.999999999999998, }