Interpolate a sf layer using the interpolation grid.
Examples
library(sf)
# Read source points
source_pts <- st_read(
dsn = system.file("gpkg/data-prefecture.gpkg", package = "distanamo"),
layer = "prefecture", quiet = TRUE
)
# Read image points
image_pts <- st_read(
dsn = system.file("gpkg/data-prefecture.gpkg", package = "distanamo"),
layer = "image-points", quiet = TRUE
)
# Read the background layer to deform
background_layer <- st_read(
dsn = system.file("gpkg/data-prefecture.gpkg", package = "distanamo"),
layer = "departement", quiet = TRUE
)
# Create the interpolation grid
igrid <- dc_create(
source_points = source_pts,
image_points = image_pts,
precision = 2,
bbox = st_bbox(background_layer)
)
# Plot various depictions of the interpolation grid
plot(igrid)
# Useful information about the interpolation grid
summary(igrid)
#> Summary of the interpolation grid:
#> Number of cells: 441
#> Precision: 50462.76 (α = 2)
#> Deformation strength: 1.041534
#> Mean absolute error: 3734.717
#> RMSE (interp - image): 4989.972
#> RMSE x (interp - image): 4060.84
#> RMSE y (interp - image): 2899.896
#> RMSE (interp - source): 42725.87
#> RMSE x (interp - source): 32080.25
#> RMSE y (interp - source): 28219.8
#> R squared: 0.9997285
# Deform the target layer
background_deformed <- dc_interpolate(
interpolation_grid = igrid,
layer_to_deform = background_layer
)
plot(st_geometry(background_deformed))
