sf (version 1.0-17)

gdal: 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, bilinear = FALSE)
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)

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.

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

bilinear

logical; use bilinear interpolation, rather than nearest neighbor?

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

Examples

if (FALSE) {
  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"))
}