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DuckDB Extensions All extensions A5 Geospatial Index

Coordinate Conversion functions in the A5 Geospatial Index DuckDB extension

Function category

Coordinate Conversion

4 functions

Translate between geographic coordinates (longitude/latitude) and A5 cell IDs in their numeric or hex string forms. Use these as your entry and exit points for indexing data into A5.

a5_cell_to_lonlat

Scalar function Coordinate Conversion
Signature
a5_cell_to_lonlat(cell: UBIGINT) → DOUBLE[2]
Arguments (Positional)
Argument cell Type UBIGINT Mode Positional Description
Description

Returns the center point [longitude, latitude] of an A5 cell

1 Example 1 
SELECT a5_cell_to_lonlat(a5_lonlat_to_cell(-122.4, 37.8, 10));

Output

a5_cell_to_lonlat(a5_lonlat_to_cell(-122.4, 37.8, 10))
(-122.37432272230853, 37.78289994807169)
Related functions

a5_hex_to_u64

Scalar function Coordinate Conversion
Signature
a5_hex_to_u64(hex: VARCHAR) → UBIGINT
Arguments (Positional)
Argument hex Type VARCHAR Mode Positional Description
Description

Converts an A5 hex string representation to a UBIGINT cell ID

1 Example 1 
SELECT a5_hex_to_u64('1600000000000000');

Output

a5_hex_to_u64('1600000000000000')
1585267068834414592
Related functions

a5_lonlat_to_cell

Scalar function Coordinate Conversion
Signature
a5_lonlat_to_cell( longitude: DOUBLE, latitude: DOUBLE, resolution: INTEGER ) → UBIGINT
Arguments (Positional)
Argument longitude Type DOUBLE Mode Positional Description
Argument latitude Type DOUBLE Mode Positional Description
Argument resolution Type INTEGER Mode Positional Description
Description

Converts a longitude/latitude coordinate to an A5 cell at the specified resolution

1 Example 1 
SELECT a5_lonlat_to_cell(-122.4194, 37.7749, 10);

Output

a5_lonlat_to_cell(-122.4194, 37.7749, 10)
1937278465245970432
Related functions

a5_u64_to_hex

Scalar function Coordinate Conversion
Signature
a5_u64_to_hex(cell: UBIGINT) → VARCHAR
Arguments (Positional)
Argument cell Type UBIGINT Mode Positional Description
Description

Converts a UBIGINT A5 cell ID to its hex string representation

1 Example 1 
SELECT a5_u64_to_hex(a5_lonlat_to_cell(-122.4, 37.8, 10));

Output

a5_u64_to_hex(a5_lonlat_to_cell(-122.4, 37.8, 10))
1ae2988000000000
Related functions