create_stars_raster: Create a 'stars' raster

In quadkeyr: Generate Raster Images from QuadKey-Identified Datasets

Create a stars raster

Description

The use of a template enables the creation of an accurate raster, even in the presence of NAs.

Usage

create_stars_raster(template, nx, ny, data, var)

Arguments

template	A sf POLYGON data.frame to use as template. Check stars::st_as_stars() documentation for more details.
nx	Integer; number of cells in x direction.
ny	Integer; number of cells in y direction.
data	A sf POLYGON data.frame with the variable we want to represent in the raster.
var	The column name of the variable to plot.

Value

A stars object.

See Also

st_as_stars, st_rasterize

Examples

# Basic workflow
# Read the data
path <- paste0(
  system.file("extdata", package = "quadkeyr"),
  "/cityA_2020_04_15_0000.csv"
)
data <- read.csv(path)
data <- format_fb_data(data)

complete_polygon_grid <- add_regular_polygon_grid(data = data)

stars_object <- create_stars_raster(
  data = complete_polygon_grid$data,
  template = complete_polygon_grid$data,
  var = "percent_change",
  nx = complete_polygon_grid$num_cols,
  ny = complete_polygon_grid$num_rows
)
stars_object

# Other workflow
grid <- create_qk_grid(
  xmin = -59,
  xmax = -57,
  ymin = -35,
  ymax = -34,
  zoom = 12
)

grid_coords <- get_qk_coord(data = grid$data)

polygrid <- grid_to_polygon(grid_coords)

data("data_provided")
data_raster <- polygrid |>
  dplyr::inner_join(data_provided,
    by = c("quadkey")
  )

raster <- create_stars_raster(
  template = data_raster,
  nx = grid$num_cols,
  ny = grid$num_rows,
  data = data_raster,
  var = "variable"
)

quadkeyr documentation built on April 3, 2025, 8:52 p.m.