Open an attribute for an HDF5 object

Usage

H5Aopen(h5obj, name)

H5Aopen_by_name(h5obj, objname = ".", name)

H5Aopen_by_idx(
  h5obj,
  n,
  objname = ".",
  index_type = h5default("H5_INDEX"),
  order = h5default("H5_ITER")
)

Arguments

h5obj: An object of class H5IdComponent representing a H5 object identifier (file, group, or dataset). See H5Fcreate(), H5Fopen(), H5Gcreate(), H5Gopen(), H5Dcreate(), or H5Dopen() to create an object of this kind.
name: The name of the attribute (character).
objname: The name of the object the attribute belongs to.
n: Opens attribute number n in the given order and index. Indexing is C-style, base-0, so the first attribute is opened with n=0.
index_type: See h5const("H5_INDEX") for possible arguments.
order: See h5const("H5_ITER") for possible arguments.

Value

An object of class H5IdComponent representing a H5 attribute identifier.

Examples

h5File <- tempfile(fileext = ".h5")
fid <- H5Fcreate(h5File)
sid <- H5Screate_simple(1)
aid <- H5Acreate(fid, "some_attribute", "H5T_NATIVE_INT", sid)
H5Aclose(aid)
H5Sclose(sid)

## open the attribute by name
aid <- H5Aopen(fid, "some_attribute")
H5Aclose(aid)

## open the attribute by name, relative to an object
aid <- H5Aopen_by_name(fid, objname = ".", name = "some_attribute")
H5Aclose(aid)

## open the first (n = 0) attribute attached to the object
aid <- H5Aopen_by_idx(fid, n = 0)
H5Aclose(aid)

H5Fclose(fid)
file.remove(h5File)
#> [1] TRUE