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Create a stars raster

Source: R/create_stars_raster.R
create_stars_raster.Rd

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 file with 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
#> stars object with 2 dimensions and 1 attribute
#> attribute(s):
#>                      Min.  1st Qu.   Median      Mean  3rd Qu.     Max. NA's
#> percent_change  -23.94377 -2.50754 1.109488 0.6168087 3.838209 28.42059  246
#> dimension(s):
#>   from to offset     delta refsys point x/y
#> x    1 18  -58.6  0.005493 WGS 84 FALSE [x]
#> y    1 22  -34.5 -0.004524 WGS 84 FALSE [y]

# 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"
)