Skip to contents

Extension of par_make_balanced for padded grids

Source: R/gridding.R
par_pad_balanced.Rd

This function utilizes anticlust::balanced_clustering() to split the input into equal size subgroups then transform the data to be compatible with the output of par_pad_grid, for which a set of padded grids of the extent of input point subsets (as recorded in the field named "CGRIDID") is generated out of input points.

Usage

par_pad_balanced(points_in = NULL, ngroups, padding)

Arguments

points_in

sf or SpatVector object. Point geometries. Default is NULL.

ngroups

integer(1). The number of groups.

padding

numeric(1). A extrusion factor to make buffer to clip actual datasets. Depending on the length unit of the CRS of input.

Value

A list of two,

  • original: exhaustive and non-overlapping grid polygons in the class of input

  • padded: a square buffer of each polygon in original. Used for computation.

See also

Other Parallelization: par_cut_coords(), par_grid(), par_grid_mirai(), par_hierarchy(), par_hierarchy_mirai(), par_make_dggrid(), par_make_grid(), par_make_h3(), par_merge_grid(), par_multirasters(), par_multirasters_mirai(), par_pad_grid(), par_split_list()

Author

Insang Song

Examples

lastpar <- par(mfrow = c(1, 1))
library(terra)
library(sf)
options(sf_use_s2 = FALSE)

ncpath <- system.file("gpkg/nc.gpkg", package = "sf")
nc <- terra::vect(ncpath)
nc_rp <- terra::spatSample(nc, 1000)

nc_gr <- par_pad_balanced(nc_rp, 10L, 1000)
nc_gr
#> $original
#>  class       : SpatVector 
#>  geometry    : points 
#>  dimensions  : 1000, 15  (geometries, attributes)
#>  extent      : -84.2674, -75.72959, 33.94107, 36.5605  (xmin, xmax, ymin, ymax)
#>  coord. ref. : lon/lat NAD27 (EPSG:4267) 
#>  names       :  AREA PERIMETER CNTY_ CNTY_ID     NAME  FIPS    FIPSNO CRESS_ID
#>  type        : <num>     <num> <num>   <num>    <chr> <chr>     <num>    <int>
#>  values      : 0.154      1.68  2030    2030  Harnett 37085 3.708e+04       43
#>                0.201     1.805  1968    1968 Randolph 37151 3.715e+04       76
#>                 0.08     1.188  2123    2123 Scotland 37165 3.716e+04       83
#>  BIR74 SID74 (and 5 more)
#>  <num> <num>             
#>   3776     6             
#>   4456     7             
#>   2255     8             
#> 
#> $padded
#>  class       : SpatVector 
#>  geometry    : polygons 
#>  dimensions  : 10, 1  (geometries, attributes)
#>  extent      : -1084.267, 924.2704, -966.0589, 1036.56  (xmin, xmax, ymin, ymax)
#>  coord. ref. :  
#>  names       : CGRIDID
#>  type        :   <num>
#>  values      :       1
#>                      2
#>                      3
#> 
par(lastpar)