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Vertices

Inspect the vertices shared by H3 cells.

cell_to_vertex

plh3.cell_to_vertex(cell: IntoExprColumn, vertex_num: int) -> pl.Expr

Return one vertex of each cell by its zero-based vertex number.

import polars as pl
import polars_h3 as plh3

df = pl.DataFrame(
    {"cell": [599686042433355775]},
    schema_overrides={"cell": pl.UInt64},
)
df.select(vertex=plh3.cell_to_vertex("cell", 0))

shape: (1, 1)
┌─────────────────────┐
│ vertex              │
│ ---                 │
│ u64                 │
╞═════════════════════╡
│ 2473183459502194687 │
└─────────────────────┘

cell_to_vertexes

plh3.cell_to_vertexes(cell: IntoExprColumn) -> pl.Expr

Return all vertices of each cell as a list.

import polars as pl
import polars_h3 as plh3

df = pl.DataFrame(
    {"cell": [599686042433355775]},
    schema_overrides={"cell": pl.UInt64},
)
df.select(vertices=plh3.cell_to_vertexes("cell"))

shape: (1, 1)
┌───────────────────────────┐
│ vertices                  │
│ ---                       │
│ list[u64]                 │
╞═══════════════════════════╡
│ [2473183459502194687, 25… │
└───────────────────────────┘

vertex_to_latlng

plh3.vertex_to_latlng(vertex: IntoExprColumn) -> pl.Expr

Return each vertex's latitude and longitude in degrees.

import polars as pl
import polars_h3 as plh3

df = pl.DataFrame(
    {"vertex": [2459626752788398079]},
    schema_overrides={"vertex": pl.UInt64},
)
df.select(coordinates=plh3.vertex_to_latlng("vertex"))

shape: (1, 1)
┌────────────────────────┐
│ coordinates            │
│ ---                    │
│ list[f64]              │
╞════════════════════════╡
│ [39.380843, 88.574962] │
└────────────────────────┘

is_valid_vertex

plh3.is_valid_vertex(vertex: IntoExprColumn) -> pl.Expr

Return whether each value is a valid H3 vertex.

import polars as pl
import polars_h3 as plh3

df = pl.DataFrame(
    {"index": [2459626752788398079, 599686042433355775]},
    schema_overrides={"index": pl.UInt64},
)
df.select(valid=plh3.is_valid_vertex("index"))

shape: (2, 1)
┌───────┐
│ valid │
│ ---   │
│ bool  │
╞═══════╡
│ true  │
│ false │
└───────┘

Vertex numbering

cell_to_vertexes retains the package's public spelling for compatibility. An invalid vertex_num can raise polars.exceptions.ComputeError.