The data used here were obtained from
https://webpages.sou.edu/~sahrk/dgg/isea.old/gen/isea3h.html and represent ISEA
discrete global grids (DGGRIDs) generated using the DGGRID software.
The original .gen files were converted to a data frame using the function dggrid_gen_to_df,
available with the dggrids package. Only resolutions 0–6 are supplied with FRK
and note that resolution 0 of ISEA3H is equal to resolution 1 in FRK. For higher
resolutions dggrids can be installed from https://github.com/andrewzm/dggrids/
using devtools.
Format
A data frame with 284,208 rows and 5 variables:
- id
grid identification number within the given resolution
- lon
longitude coordinate
- lat
latitude coordinate
- res
DGGRID resolution (0 – 6)
- centroid
A 0-1 variable, indicating whether the point describes the centroid of the polygon, or whether it is a boundary point of the polygon