hexify_cell_to_index: Convert cell coordinates to index string

In hexify: Equal-Area Hex Grids on the 'Snyder' 'ISEA' 'Icosahedron'

Convert cell coordinates to index string

Description

Converts DGGRID cell coordinates (face, i, j) to a hierarchical index string. The index type is automatically selected based on aperture unless specified.

Usage

hexify_cell_to_index(
  face,
  i,
  j,
  resolution,
  aperture = 3L,
  index_type = c("auto", "z3", "z7", "zorder")
)

Arguments

face	Face/quad number (0-19)
i	I coordinate
j	J coordinate
resolution	Resolution level
aperture	Aperture (3, 4, or 7)
index_type	Index encoding: "auto" (default), "z3", "z7", or "zorder"

Details

Default index types by aperture:

• Aperture 3: Z3 (optimized digit selection)

• Aperture 4: Z-order (Morton curve)

• Aperture 7: Z7 (hierarchical with Class III handling)

Value

Index string (e.g., "051223")

See Also

Other hierarchical index: hexify_compare_indices(), hexify_default_index_type(), hexify_get_children(), hexify_get_parent(), hexify_get_resolution(), hexify_index_to_cell(), hexify_index_to_lonlat(), hexify_is_valid_index_type(), hexify_lonlat_to_index(), hexify_z7_canonical()

Examples

idx <- hexify_cell_to_index(5, 10, 15, resolution = 3, aperture = 3)

hexify documentation built on March 1, 2026, 1:07 a.m.