Geospatial function

[davidjianu39]

Hello!

I was wondering if is there any function in Ibis which converts a string into a polygon/point? something similar to ST_ GeomFromText() in SQL? Thank you very much in advance!

[cpcloud]

@davidjianu39 It looks like there's no way to do this with ibis right now. We are using ST_GeomFromText to construct literal values from shapely types, but it appears we do not have an API to convert columns or literals of strings to geometries or geographies.

Is this something you'd be interested in implementing?

[rcutler-ursa]

Along these lines, how does one create a literal geometry object that one can perform spatial queries with? For example,

data = data.filter(data["geometry"].overlaps(bounding_box))

where bounding_box is a polygon not in the database, but rather provided as a constant in the program. Something like:

bounding_box = ibis.literal("POLYGON((-71 43, -72 43, -72 44, -71 44, -71 43))", type="geometry")

[cpcloud]

You can construct geometry literals using shapely types:

In [9]: import ibis

In [10]: import shapely

In [11]: ibis.literal(shapely.geometry.Point(0, 0))
Out[11]: value: point = <shapely.geometry.point.Point object at 0x7f1a824e0820>

In [12]: ibis.literal(shapely.geometry.Point(0, 0)).type()
Out[12]: Point(nullable=True)

and you can also use tuples in the case of point and similarly for polygon

In [25]: ibis.literal(((0, 1), (1, 0), (0, 3)), type="polygon")
Out[25]: value: polygon = ((0, 1), (1, 0), (0, 3))

In [26]: ibis.literal(((0, 1), (1, 0), (0, 3)), type="polygon").type()
Out[26]: Polygon(nullable=True)

[rcutler-ursa]

Thanks! Building a shapely.geometry.Polygon worked. Appreciate the quick response.