Convert Icosa Triangle to Quad IJ coordinates

Converts icosahedral triangle coordinates directly to Quad IJ, combining the transformation and quantization steps.

Usage

hexify_icosa_tri_to_quad_ij(
  icosa_triangle_face,
  icosa_triangle_x,
  icosa_triangle_y,
  resolution,
  aperture = 3L
)

Arguments

icosa_triangle_face

Triangle face number (0-19)

icosa_triangle_x

X coordinate on triangle face

icosa_triangle_y

Y coordinate on triangle face

resolution

Grid resolution level

aperture

Grid aperture: 3, 4, or 7

Value

List with components:

quad

Quad number (0-11)

i

Integer cell index along first axis

j

Integer cell index along second axis

See also

Other coordinate conversion: hexify_cell_id_to_quad_ij(), hexify_cell_to_icosa_tri(), hexify_cell_to_lonlat(), hexify_cell_to_plane(), hexify_cell_to_quad_ij(), hexify_cell_to_quad_xy(), hexify_grid_cell_to_lonlat(), hexify_grid_to_cell(), hexify_icosa_tri_to_plane(), hexify_icosa_tri_to_quad_xy(), hexify_lonlat_to_cell(), hexify_lonlat_to_plane(), hexify_lonlat_to_quad_ij(), hexify_quad_ij_to_cell(), hexify_quad_ij_to_icosa_tri(), hexify_quad_ij_to_xy(), hexify_quad_xy_to_cell(), hexify_quad_xy_to_icosa_tri(), hexify_roundtrip_test()

Examples

if (FALSE) { # \dontrun{
# First get triangle coordinates from lon/lat
fwd <- hexify_forward(lon = 2.35, lat = 48.86)

# Then convert to quad IJ
quad_ij <- hexify_icosa_tri_to_quad_ij(
  icosa_triangle_face = fwd$face,
  icosa_triangle_x = fwd$tx,
  icosa_triangle_y = fwd$ty,
  resolution = 10,
  aperture = 3
)
print(quad_ij)
} # }