gdal: functions to interact with gdal not meant to be called...

In sf: Simple Features for R

functions to interact with gdal not meant to be called directly by users (but e.g. by stars::read_stars)

Description

functions to interact with gdal not meant to be called directly by users (but e.g. by stars::read_stars)

Usage

gdal_read(
  x,
  ...,
  options = character(0),
  driver = character(0),
  read_data = TRUE,
  NA_value = NA_real_,
  RasterIO_parameters = list()
)

gdal_write(
  x,
  ...,
  file,
  driver = "GTiff",
  options = character(0),
  type = "Float32",
  NA_value = NA_real_,
  geotransform,
  update = FALSE,
  scale_offset = c(1, 0)
)

gdal_inv_geotransform(gt)

gdal_crs(file, options = character(0))

gdal_metadata(
  file,
  domain_item = character(0),
  options = character(0),
  parse = TRUE
)

gdal_subdatasets(file, options = character(0), name = TRUE)

gdal_polygonize(
  x,
  mask = NULL,
  file = tempfile(),
  driver = "GTiff",
  use_integer = TRUE,
  geotransform,
  breaks = classInt::classIntervals(na.omit(as.vector(x[[1]])))$brks,
  use_contours = FALSE,
  contour_lines = FALSE,
  connect8 = FALSE,
  ...
)

gdal_rasterize(sf, x, gt, file, driver = "GTiff", options = character())

gdal_extract(
  f,
  pts,
  resampling = c("nearest", "bilinear", "cubic", "cubicspline")
)

gdal_read_mdim(
  file,
  array_name = character(0),
  options = character(0),
  offset = integer(0),
  count = integer(0),
  step = integer(0),
  proxy = FALSE,
  debug = FALSE
)

gdal_write_mdim(
  file,
  driver,
  dimx,
  cdl,
  wkt,
  xy,
  ...,
  root_group_options = character(0),
  options = character(0),
  as_float = TRUE
)

gdal_create(f, nxy, values, crs, xlim, ylim)

Arguments

x	character vector, possibly of length larger than 1 when more than one raster is read
...	ignored
options	character; driver specific options regarding reading or creating the dataset
driver	character; driver short name; when empty vector, driver is auto-detected.
read_data	logical; if FALSE, only the imagery metadata is returned
NA_value	(double) non-NA value to use for missing values; if NA, when writing missing values are not specially flagged in output dataset, when reading the default (dataset) missing values are used (if present / set).
RasterIO_parameters	list with named parameters to GDAL's RasterIO; see the stars::read_stars documentation.
file	file name
type	gdal write type
geotransform	length 6 numeric vector with GDAL geotransform parameters.
update	logical; TRUE if in an existing raster file pixel values shall be updated.
scale_offset	length 2 numeric; contains scale and offset values
gt	double vector of length 6
domain_item	character vector of length 0, 1 (with domain), or 2 (with domain and item); use "" for the default domain, use NA_character_ to query the domain names.
parse	logical; should metadata be parsed into a named list (TRUE) or returned as character data?
name	logical; retrieve name of subdataset? If FALSE, retrieve description
mask	stars object with NA mask (0 where NA), or NULL
use_integer	boolean; if TRUE, raster values are read as (and rounded to) unsigned 32-bit integers values; if FALSE they are read as 32-bit floating points numbers. The former is supposedly faster.
breaks	numeric vector with break values for contour polygons (or lines)
use_contours	logical;
contour_lines	logical;
connect8	logical; if TRUE use 8 connection algorithm, rather than 4
sf	object of class sf
f	character; file name
pts	points matrix
resampling	character; resampling method; for method cubic or cubicspline, stars_proxy objects should be used and GDAL should have version >= 3.10.0
array_name	array name
offset	offset (pixels)
count	number of pixels to read
step	step size (pixels)
proxy	logical; return proxy object?
debug	logical; print debug messages?
dimx	integer named vector with dimensions of object
cdl	list with variables, each having a named dim attribute
wkt	character; WKT of crs
xy	character; names of the spatial x and y dimension
root_group_options	character; driver specific options regarding the creation of the root group
as_float	logical; when TRUE write 4-byte floating point numbers, when FALSE write 8-byte doubles.
nxy	integer vector of length 2
values	fill value
crs	object of class crs
xlim	numeric
ylim	numeric

Details

These functions are exported for the single purpose of being used by package stars, they are not meant to be used directly and may change or disappear without prior notice or deprecation warnings.

gdal_inv_geotransform returns the inverse geotransform

gdal_crs reads coordinate reference system from GDAL data set

get_metadata gets metadata of a raster layer

gdal_subdatasets returns the subdatasets of a gdal dataset

Value

object of class crs, see st_crs.

named list with metadata items

gdal_subdatasets returns a zero-length list if file does not have subdatasets, and else a named list with subdatasets.

Examples

## Not run: 
  f = system.file("tif/L7_ETMs.tif", package="stars")
  f = system.file("nc/avhrr-only-v2.19810901.nc", package = "stars")
  gdal_metadata(f)
  gdal_metadata(f, NA_character_)
  try(gdal_metadata(f, "wrongDomain"))
  gdal_metadata(f, c("", "AREA_OR_POINT"))

## End(Not run)

sf documentation built on June 8, 2025, 10:18 a.m.