h5_createAttribute: Create HDF5 attribute

In grimbough/rhdf5: R Interface to HDF5

Create HDF5 attribute

Description

R function to create an HDF5 attribute and defining its dimensionality.

Usage

h5createAttribute(
  obj,
  attr,
  dims,
  maxdims = dims,
  file,
  storage.mode = "double",
  H5type = NULL,
  size = NULL,
  encoding = NULL,
  cset = NULL,
  native = FALSE
)

Arguments

obj	The name (character) of the object the attribute will be attatched to. For advanced programmers it is possible to provide an object of class H5IdComponent representing a H5 object identifier (file, group, dataset). See H5Fcreate(), H5Fopen(), H5Gcreate(), H5Gopen(), H5Dcreate(), H5Dopen() to create an object of this kind.
attr	Name of the attribute to be created.
dims	The dimensions of the attribute as a numeric vector. If NULL, a scalar dataspace will be created instead.
maxdims	The maximum extension of the attribute.
file	The filename (character) of the file in which the dataset will be located. For advanced programmers it is possible to provide an object of class H5IdComponent representing an H5 location identifier. See H5Fcreate(), H5Fopen(), H5Gcreate(), H5Gopen() to create an object of this kind. The file argument is not required, if the argument obj is of type H5IdComponent.
storage.mode	The storage mode of the data to be written. Can be obtained by storage.mode(mydata).
H5type	Advanced programmers can specify the datatype of the dataset within the file. See h5const("H5T") for a list of available datatypes. If H5type is specified the argument storage.mode is ignored. It is recommended to use storage.mode
size	The maximum string length when storage.mode='character'. If this is specified, HDF5 stores each string of attr as fixed length character arrays. Together with compression, this should be efficient. If this argument is set to NULL, HDF5 will instead store variable-length strings.
encoding	The encoding of the string data type i.e. when storage.mode = 'character'. Valid options are "ASCII" and "UTF-8".
cset	Deprecated in favour of the encoding argument.
native	An object of class logical. If TRUE, array-like objects are treated as stored in HDF5 row-major rather than R column-major orientation. Using native = TRUE increases HDF5 file portability between programming languages. A file written with native = TRUE should also be read with native = TRUE

Details

Creates a new attribute and attaches it to an existing HDF5 object. The function will fail, if the file doesn't exist or if there exists already another attribute with the same name for this object.

You can use h5writeAttribute() immediately. It will create the attribute for you.

Value

Returns TRUE is attribute was created successfully and FALSE otherwise.

Author(s)

Bernd Fischer

References

https://portal.hdfgroup.org/display/HDF5

See Also

h5createFile(), h5createGroup(), h5createDataset(), h5read(), h5write(), rhdf5

Examples

h5File <- tempfile(pattern = "ex_createAttribute.h5")
h5createFile(h5File)
h5write(1:1, h5File, "A")
fid <- H5Fopen(h5File)
did <- H5Dopen(fid, "A")
h5createAttribute (did, "time", c(1,10))
H5Dclose(did)
H5Fclose(fid)

grimbough/rhdf5 documentation built on Dec. 9, 2024, 8:40 p.m.