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Create an (empty) Zarr array

Source: R/write_data.R
create_empty_zarr_array.Rd

Create an (empty) Zarr array

Usage

create_empty_zarr_array(
  zarr_array_path,
  dim,
  chunk_dim,
  data_type,
  order = "F",
  compressor = use_zstd(),
  fill_value,
  nchar = NULL,
  dimension_separator = if (zarr_version == 2L) "." else "/",
  dimension_names = NULL,
  zarr_version = 3L
)

Arguments

zarr_array_path

Character vector of length 1 giving the path to the new Zarr array.

dim

Dimensions of the new array. Should be a numeric vector with the same length as the number of dimensions.

chunk_dim

Dimensions of the array chunks. Should be a numeric vector with the same length as the dim argument.

data_type

Character vector giving the data type of the new array. Valid options are: "integer", "double", "character", "logical", which are based on standard R data types. You can also use the analogous Numpy formats: "|i1", "<i2", "<i4", "<f4", "<f8", "|S", "|b1". If this argument isn't provided the fill_value will be used to determine the datatype.

order

Define the layout of the bytes within each chunk. Valid options are 'column', 'row', 'F' & 'C'. 'column' or 'F' will specify "column-major" ordering, which is how R arrays are arranged in memory. 'row' or 'C' will specify "row-major" order.

compressor

What (if any) compression tool should be applied to the array chunks. The default is to use zstd compression. Supplying NULL will disable chunk compression. See compressors for more details.

fill_value

The default value for uninitialized portions of the array. Does not have to be provided, in which case the default for the specified data type will be used.

nchar

For datatype = "character" this parameter gives the maximum length of the stored strings. It is an error not to specify this for a character array, but it is ignored for other data types.

dimension_separator

The character used to to separate the dimensions in the names of the chunk files. Valid options are limited to "." and "/".

dimension_names

Optional character vector with the same length as dim.

zarr_version

The version of the Zarr specification to use. Currently, either 2 or 3. The default is 3.

Value

If successful returns (invisibly) TRUE. However this function is primarily called for the size effect of initialising a Zarr array location and creating the .zarray metadata.

See also

write_zarr_array(), update_zarr_array()

Examples


new_zarr_array <- file.path(tempdir(), "temp.zarr")
create_empty_zarr_array(new_zarr_array,
  dim = c(10, 20), chunk_dim = c(2, 5),
  data_type = "integer"
)