Package index • dggridR

Grid Construction

Construct and configure a Discrete Global Grid System (dggs) specification.

dgconstruct(): Construct a discrete global grid system (dggs) object
dgsetres(): Set the resolution of a dggs object
dgverify(): Verify that a dggs object has appropriate values

Grid Information

Inspect a dggs object: print a summary, retrieve per-resolution statistics, count cells, and automatically select a resolution from a target area, spacing, or characteristic length scale.

dginfo(): Print info about a dggs object to the screen
dggetres(): Get table of grid resolution information
dgmaxcell(): Get largest cell id for a dggs
dg_closest_res(): Determine an appropriate grid resolution based on input data.
dg_closest_res_to_area(): Determine resolution based on desired area
dg_closest_res_to_cls(): Determine an appropriate grid resolution based on a desired characteristic length scale of the cells.
dg_closest_res_to_spacing(): Determine grid resolution from desired spacing.

Grid Materialization

Generate grid cell boundaries as sf geometries for plotting and spatial analysis.

dgearthgrid(): Return the coordinates constituting the boundary of cells for the entire Earth
dgcellstogrid(): Return boundary coordinates for specified cells
dgrectgrid(): Return the coordinates constituting the boundary of cells within a specified region
dgshptogrid(): Return boundary coordinates for cells intersecting a shapefile

Point Aggregation

Aggregate lon/lat point data into grid cells. dgpoints_to_cells() returns an sf grid (optionally with per-cell counts); dgbin_points() returns a lightweight data frame of per-cell statistics.

dgpoints_to_cells(): Return grid cells containing input points
dgbin_points(): Aggregate point data into grid cells

Cell Relationships

Query spatial relationships between cells. dgneighbors() finds adjacent hexagonal cells; dgchildren() and dgparent() navigate the grid hierarchy across resolution levels.

dgneighbors(): Return neighboring cell IDs for each input cell
dgchildren(): Return immediate child cell IDs for each input cell
dgparent(): Return parent cell ID for each input cell

Coordinate Conversion

Convert between the five cell address systems supported by DGGRID: GEO (geographic lon/lat), SEQNUM (globally unique integer cell ID), Q2DI (quad-based integer coordinates), Q2DD (quad-based double coordinates), and PROJTRI (projected triangle coordinates). Functions follow the naming convention dgINPUT_to_OUTPUT. dgGEO_to_SEQNUM() and dgSEQNUM_to_GEO() are the most commonly used.

dgGEO_to_GEO(): Convert from GEO to GEO
dgGEO_to_PLANE(): Convert from GEO to PLANE
dgGEO_to_PROJTRI(): Convert from GEO to PROJTRI
dgGEO_to_Q2DD(): Convert from GEO to Q2DD
dgGEO_to_Q2DI(): Convert from GEO to Q2DI
dgGEO_to_SEQNUM(): Convert from GEO to SEQNUM
dgSEQNUM_to_GEO(): Convert from SEQNUM to GEO
dgSEQNUM_to_PLANE(): Convert from SEQNUM to PLANE
dgSEQNUM_to_PROJTRI(): Convert from SEQNUM to PROJTRI
dgSEQNUM_to_Q2DD(): Convert from SEQNUM to Q2DD
dgSEQNUM_to_Q2DI(): Convert from SEQNUM to Q2DI
dgSEQNUM_to_SEQNUM(): Convert from SEQNUM to SEQNUM
dgQ2DI_to_GEO(): Convert from Q2DI to GEO
dgQ2DI_to_PLANE(): Convert from Q2DI to PLANE
dgQ2DI_to_PROJTRI(): Convert from Q2DI to PROJTRI
dgQ2DI_to_Q2DD(): Convert from Q2DI to Q2DD
dgQ2DI_to_Q2DI(): Convert from Q2DI to Q2DI
dgQ2DI_to_SEQNUM(): Convert from Q2DI to SEQNUM
dgQ2DD_to_GEO(): Convert from Q2DD to GEO
dgQ2DD_to_PLANE(): Convert from Q2DD to PLANE
dgQ2DD_to_PROJTRI(): Convert from Q2DD to PROJTRI
dgQ2DD_to_Q2DD(): Convert from Q2DD to Q2DD
dgQ2DD_to_Q2DI(): Convert from Q2DD to Q2DI
dgQ2DD_to_SEQNUM(): Convert from Q2DD to SEQNUM
dgPROJTRI_to_GEO(): Convert from PROJTRI to GEO
dgPROJTRI_to_PLANE(): Convert from PROJTRI to PLANE
dgPROJTRI_to_PROJTRI(): Convert from PROJTRI to PROJTRI
dgPROJTRI_to_Q2DD(): Convert from PROJTRI to Q2DD
dgPROJTRI_to_Q2DI(): Convert from PROJTRI to Q2DI
dgPROJTRI_to_SEQNUM(): Convert from PROJTRI to SEQNUM

Data

Example dataset and helper utilities bundled with the package.

dgquakes: All earthquakes with magnitude >=3.0 earthquakes for 2015
dg_shpfname_south_africa(): National border of South Africa