Read or write data using GDAL's multidimensional array API

Usage

read_mdim(
  filename,
  variable = character(0),
  ...,
  options = character(0),
  raster = NULL,
  offset = integer(0),
  count = integer(0),
  step = integer(0),
  proxy = FALSE,
  debug = FALSE,
  bounds = TRUE,
  curvilinear = NA
)

write_mdim(
  x,
  filename,
  driver = detect.driver(filename),
  ...,
  root_group_options = character(0),
  options = character(0),
  as_float = TRUE
)

Arguments

filename: name of the source or destination file or data source
variable: name of the array to be read; if `"?"`, a list of array names is returned, with group name as list element names.
...: ignored
options: character; driver specific options regarding the opening (read_mdim) or creation (write_mdim) of the dataset
raster: names of the raster variables (default: first two dimensions)
offset: integer; offset for each dimension (pixels) of sub-array to read, defaults to 0 for each dimension(requires sf >= 1.0-9)
count: integer; size for each dimension (pixels) of sub-array to read (default: read all); a value of NA will read the corresponding dimension entirely; counts are relative to the step size (requires sf >= 1.0-9)
step: integer; step size for each dimension (pixels) of sub-array to read; defaults to 1 for each dimension (requires sf >= 1.0-9)
proxy: logical; return proxy object? (not functional yet)
debug: logical; print debug info?
bounds: logical or character: if TRUE tries to infer from "bounds" attribute; if character, named vector of the form c(longitude="lon_bnds", latitude="lat_bnds") with names dimension names
curvilinear: control reading curvilinear (geolocation) coordinate arrays; if NA try reading the x/y dimension names; if character, defines the arrays to read; if FALSE do not try; see also read_stars
x: stars object
driver: character; driver name
root_group_options: character; driver specific options regarding the creation of the root group
as_float: logical; if TRUE write 4-byte floating point numbers, if FALSE write 8-byte doubles

Details

it is assumed that the first two dimensions are easting and northing

Examples

set.seed(135)
m = matrix(runif(10), 2, 5)
names(dim(m)) = c("stations", "time")
times = as.Date("2022-05-01") + 1:5
pts = st_as_sfc(c("POINT(0 1)", "POINT(3 5)"))
s = st_as_stars(list(Precipitation = m)) |>
 st_set_dimensions(1, values = pts) |>
 st_set_dimensions(2, values = times)
nc = tempfile(fileext=".nc")
if (compareVersion(sf_extSoftVersion()["GDAL"], "3.4.0") > -1) {
  write_mdim(s, nc)
  # try ncdump on the generated file
  print(read_mdim(nc))
}
#> Warning: GDAL Error 6: SetIndexingVariable() not implemented
#> Warning: GDAL Error 6: SetIndexingVariable() not implemented
#> stars object with 2 dimensions and 1 attribute
#> attribute(s):
#>                      Min.   1st Qu.    Median      Mean  3rd Qu.      Max.
#> Precipitation  0.03524588 0.3224987 0.3772574 0.4289465 0.511113 0.9204841
#> dimension(s):
#>          from to     offset  delta refsys point                   values
#> stations    1  2         NA     NA     NA  TRUE POINT (0 1), POINT (3 5)
#> time        1  5 2022-05-02 1 days   Date    NA                     NULL

Read or write data using GDAL's multidimensional array API

Usage

Arguments

Details

See also

Examples