Function reference • icosa

Grid creation

Items relevant for creating grids.

trigrid-class trigrid: A triangular icosahedral grid

hexagrid-class hexagrid: Construct a penta-hexagonal icosahedral grid

triguide: Tessellation guide to trigrid objects

hexguide: Tessellation guide to hexagrid objects

Grid properties

Functions useful to access properties, attributes and subparts of the grid.

vertices(): The vertices of an icosahedral grid object

orientation() `orientation<-`(): Extracting and setting the grid orientation

edges(): The edges of a 3d object

faces(): The face names of a trigrid or hexagrid object

length(<trigrid>) length(<gridlayer>): The number of faces in a trigrid or hexagrid class object.

centers(): The face centers of an icosahedral grid object

edgelength(): Lengths of grid edges

surfacearea(): Areas of grid cell surfaces

trishape(): Shape distortions of the triangular faces and subfaces

pos(): Position of face centers and vertices on a grid

Grids as graphs

Functions relevant to treating the icosahedral grids as graph (network objects). These methods rely and interface with the ‘igraph’ package.

gridgraph(): Create or instantiate an graph class graph from the faces of an icosahedral grid

vicinity(): The neighbouring faces of faces in an icosahedral grid

Grid operations

Functions useful for modifying grid structure.

SpLines(): Create a SpatialLines class object from an icosahedral grid

SpPolygons(): Spatial polygons from an icosahedral grid

newsf(): Add a sf object to a predefined slot in a trigrid or hexagrid object

newsp(): Add a SpatialPolygons object to a predefined slot in a trigrid or hexagrid object

newgraph(): Add an igraph object to a predefined slot in an icosahedral grid

rotate rotate(<trigrid>): Rotation of trigrid and hexagrid objects

translate(): Translating an icosahedral grid object in 3d Cartesian space

subset subset(<trigrid>) subset(<hexagrid>) `[`(<trigrid>,<ANY>,<ANY>) subset(<gridlayer>): Subsetting an icosahedral grid or data layers organized with them

2D plotting

Functions useful for 2d plotting and interaction with 2d plots. These functions rely either on the sf or sp packages.

plot plot(<trigrid>,<ANY>) plot(<facelayer>,<ANY>) plot(<trigrid>,<numeric>) plot(<trigrid>,<array>) plot(<trigrid>,<table>) plot(<trigrid>,<character>) plot(<trigrid>,<logical>): Plot method for the trigrid, hexagrid or facelayer classes

lines(<trigrid>): Lines method for the trigrid and hexagrid classes

gridlabs(): Labels of grid vertices, faces and edges.

cellocator(): Locate grid faces based on their positions on a map

heatMapLegend(): Legend for a heatmap with predefined colors.

3D plotting

Functions useful for 3d plotting. These items rely on the ‘rgl’ package.

plot3d(): 3d plotting of an icosahedral grid, its subset or a data layer

lines3d lines3d(<trigrid>) lines3d(<Line>) lines3d(<Lines>) lines3d(<SpatialLines>) lines3d(<SpatialLinesDataFrame>) lines3d(<Polygon>) lines3d(<Polygons>) lines3d(<SpatialPolygons>) lines3d(<SpatialPolygonsDataFrame>): Methods of 3d line plotting

faces3d(): Methods of 3D face plotting.

gridlabs3d(): Display the names of the grid elements in 3d plots.

guides3d(): Guides for 3d spherical plotting.

Interfacing

Items needed for external data to interact with the grids.

locate(): Basic lookup function of coordinates on an icosahedral grid

occupied(): Faces occupied by the specified object

resample resample(<SpatRaster>,<trigrid>) resample(<facelayer>,<trigrid>) resample(<facelayer>,<SpatRaster>): Resampling of data involving a trigrid or a hexagrid object.

gridensity(): Icosahedral grid-based density estimation

Gridlayer/facelayer

In development native grid-based data containers.

facelayer-class facelayer: A facelayer linked to a trigrid or hexagrid object

names(<gridlayer>): The face names in a facelayer class object

values() `values<-`(): Extract and replace values from a gridlayer-derived object (e.g. link{facelayer}).

resample resample(<SpatRaster>,<trigrid>) resample(<facelayer>,<trigrid>) resample(<facelayer>,<SpatRaster>): Resampling of data involving a trigrid or a hexagrid object.

`[`(<gridlayer>,<ANY>,<missing>) `[`(<gridlayer>,<SpatExtent>,<missing>) `[<-`(<gridlayer>,<ANY>,<ANY>): Extraction from a gridlayer using indices

Utilities

Functions for general use in spherical geometry, such as distance measurement, coordinate conversion. In general, these apply to point data.

rpsphere(): Random point generation on the surface of a sphere

CarToPol(): Conversion of 3d Cartesian coordinates to polar coordinates

PolToCar(): Conversion of polar coordinates to 3d Cartesian coordinates

arcdist(): Calculation of distances along arcs

arcdistmat(): Calculation of distance matrices along arcs

arcpoints(): Calculation of point coordinates along an arc

arcs(): Function to plot a set of great circle arcs between points

surfacecentroid(): Surface centroid point of a spherical point cloud

chullsphere(): Spherical convex hull.