用于计算距离的笛卡尔积的 BigQuery Geography 函数

Question

我需要计算一组 GEO 点的距离的笛卡尔积。更具体地说，计算从第一个点到所有其他 5 个点的距离，然后是从第二个点到所有其他点的距离等。

想知道是否有可以有效执行此类计算的 BigQuery Geography 函数。

另一种方法是显式地成对进行，这是一种蛮力方法。

POINT(-95.665885 29.907145)
POINT(-95.636533 29.757219)
POINT(-95.652796 29.89204)
POINT(-84.27087 33.991642)
POINT(-84.466853 33.987008)

Answer 1

我尝试使用您的示例数据创建示例：

//Creating a temporary table with your data
with t as 
(Select * from UNNEST(
['POINT(-95.665885 29.907145)',
'POINT(-95.636533 29.757219)',
'POINT(-95.652796 29.89204)',
'POINT(-84.27087 33.991642)',
'POINT(-84.466853 33.987008)']) f
)

//Doing a cross join of the created table with itself, filtering some cases to avoid calculating the distance of a point to itself and calculating the distance between the points

select
  t.f point_1, 
  t2.f point_2, 
  ST_DISTANCE(ST_GeogFromText(t.f), ST_GeogFromText(t2.f))
from t cross join t t2
where t.f <> t2.f
group by point_1, point_2

是您要找的吗？当然如果你认为两点之间的距离是相同的，无论它们的顺序如何，它都可以优化。

用于计算距离的笛卡尔积的 BigQuery Geography 函数

BigQuery Geography function to compute cartesian product of distances

gis

google-bigquery