xdggs.HealpixInfo

xdggs.HealpixInfo#

class xdggs.HealpixInfo(level, ellipsoid=None, indexing_scheme='nested')#

Grid information container for healpix grids.

Parameters:

  • level (int) – Grid hierarchical level. A higher value corresponds to a finer grid resolution with smaller cell areas. The number of cells covering the whole sphere usually grows exponentially with increasing level values, ranging from 5-100 cells at level 0 to millions or billions of cells at level 10+ (the exact numbers depends on the specific grid).

  • indexing_scheme ({"nested", "ring", "zuniq", "nuniq"}, default: "nested") – The indexing scheme of the healpix grid.

    Warning

    Note that "nuniq" is currently not supported as the underlying library (healpix-geo) does not support it.

  • ellipsoid (ellipsoid-like, optional) – The reference ellipsoid. If not passed, a sphere is assumed.

__init__(level, ellipsoid=None, indexing_scheme='nested')#

Methods

__init__(level[, ellipsoid, indexing_scheme])

cell_boundaries(cell_ids[, backend])

Derive cell boundary polygons from cell ids

cell_ids2geographic(cell_ids)

Convert cell ids to geographic coordinates

from_dict(mapping)

construct a HealpixInfo object from a mapping of attributes

geographic2cell_ids(lon, lat)

Convert cell ids to geographic coordinates

to_dict()

Dump the normalized grid parameters.

zoom_to(cell_ids, level)

Attributes

ellipsoid

The ellipsoid

indexing_scheme

The indexing scheme of the grid

nest

indexing_scheme as the healpy-compatible nest parameter

nside

resolution as the healpy-compatible nside parameter

valid_parameters

level

The hierarchical level of the grid
Contents