Spatial Extension for BigQuery

Spatial Extension for BigQuery

measurements

This module contains functions that compute measurements of distance, area and angles. There are also functions to compute geometry values determined by measurements.

ST_ANGLE

Description

Finds the angle formed by two adjacent segments defined by 3 points. The result will be the (positive clockwise) angle with origin on the startPoint-midPoint segment, or its explementary angle if required.

  • startPoint: GEOGRAPHY start Point Coordinates.
  • midPoint: GEOGRAPHY mid Point Coordinates.
  • endPoint: GEOGRAPHY end Point Coordinates.
  • mercator: BOOLEAN|NULL if calculations should be performed over Mercator or WGS84 projection. If NULL the default value false is used.

Return type

FLOAT64

Example

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SELECT carto-os.measurements.ST_ANGLE(ST_GEOGPOINT(-3.70325 ,40.4167), ST_GEOGPOINT(-4.70325 ,10.4167), ST_GEOGPOINT(-5.70325 ,40.4167), false);
-- 3.933094586038578

ST_AZIMUTH

Description

Takes two points and finds the geographic bearing between them, i.e. the angle measured in degrees from the north line (0 degrees).

  • startPoint: GEOGRAPHY starting Point.
  • endPoint: GEOGRAPHY ending Point.

Return type

FLOAT64

Example

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SELECT carto-os.measurements.ST_AZIMUTH(ST_GEOGPOINT(-3.70325 ,40.4167), ST_GEOGPOINT(-4.70325 ,41.4167));
-- -36.75052908494255

ST_MINKOWSKIDISTANCE

Description

Calculate the Minkowski p-norm distance between two features.

  • geog: ARRAY<GEOGRAPHY> featureCollection.
  • p: FLOAT64 minkowski p-norm distance parameter. 1: Manhattan distance. 2: Euclidean distance. 1 =< p <= infinity. If NULL the default value 2 is used.

Return type

ARRAY<STRING>

Example

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SELECT carto-os.measurements.ST_MINKOWSKIDISTANCE([ST_GEOGPOINT(10,10),ST_GEOGPOINT(13,10)],2);
-- ["0,0.3333333333333333","0.3333333333333333,0"]

VERSION

Description

Returns the current version of the measurements module.

Return type

STRING

Example

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SELECT carto-os.measurements.VERSION();
-- 1.0.0