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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_hierarchy(), par_make_grid(), par_merge_grid(), par_multirasters(), par_pad_grid(), par_split_list()

Author

Insang Song

Examples

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      : -84.24941, -75.79698, 33.88802, 36.55712  (xmin, xmax, ymin, ymax)
#>  coord. ref. : lon/lat NAD27 (EPSG:4267) 
#>  names       :  AREA PERIMETER CNTY_ CNTY_ID        NAME  FIPS    FIPSNO
#>  type        : <num>     <num> <num>   <num>       <chr> <chr>     <num>
#>  values      : 0.078     1.202  2056    2056      Graham 37075 3.708e+04
#>                0.125     2.868  2156    2156    Carteret 37031 3.703e+04
#>                0.153     2.206  1832    1832 Northampton 37131 3.713e+04
#>  CRESS_ID BIR74 SID74 (and 5 more)
#>     <int> <num> <num>             
#>        38   415     0             
#>        16  2414     5             
#>        66  1421     9             
#> 
#> $padded
#>  class       : SpatVector 
#>  geometry    : polygons 
#>  dimensions  : 10, 1  (geometries, attributes)
#>  extent      : -1084.249, 924.203, -966.112, 1036.557  (xmin, xmax, ymin, ymax)
#>  coord. ref. :  
#>  names       : CGRIDID
#>  type        :   <num>
#>  values      :       1
#>                      2
#>                      3
#>