h5createDataset: Create HDF5 dataset

In patperry/rhdf5: HDF5 interface to R

Description

R function to create an HDF5 dataset and defining its dimensionality and compression behaviour.

Usage

h5createDataset (file, dataset, 
		dims, maxdims = dims, 
		storage.mode = "double", H5type = NULL, 
		size = NULL, chunk = NULL, level = 6)

Arguments

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 a H5 location identifier (file or group). See H5Fcreate, H5Fopen, H5Gcreate, H5Gopen to create an object of this kind.
dataset	Name of the dataset to be created. The name can contain group names, e.g. 'group/dataset', but the function will fail, if the group does not yet exist.
dims	The dimensions of the array as they will appear in the file. Note, the dimensions will appear in inverted order when viewing the file with a C-programm (e.g. HDFView), because the fastest changing dimension in R is the first one, whereas the fastest changing dimension in C is the last one.
maxdims	The maximum extension of the array.
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	For storage.mode='character' the maximum string length has to be specified. HDF5 then stores the string as fixed length character vectors. Together with compression, this should be efficient.
chunk	The chunk size used to store the dataset. It is an integer vector of the same length as dims. This argument is usually set together with a compression property (argument level).
level	The compression level used. An integer value between 0 (no compression) and 9 (highest and slowest compression).

Details

Creates a new dataset. in an existing HDF5 file. The function will fail, if the file doesn't exist or if there exists already another dataset with the same name within the specified file.

Value

Returns TRUE is dataset was created successfully and FALSE otherwise.

Author(s)

Bernd Fischer

References

http://www.hdfgroup.org/HDF5

See Also

h5createFile, h5createGroup, h5read, h5write, rhdf5

Examples

h5createFile("ex_createDataset.h5")

# create dataset with compression
h5createDataset("ex_createDataset.h5", "A", c(5,8), storage.mode = "integer", chunk=c(5,1), level=7)

# create dataset without compression
h5createDataset("ex_createDataset.h5", "B", c(5,8), storage.mode = "integer")
h5createDataset("ex_createDataset.h5", "C", c(5,8), storage.mode = "double")

# write data to dataset
h5write(matrix(1:40,nr=5,nc=8), file="ex_createDataset.h5", name="A")
# write second column
h5write(matrix(1:5,nr=5,nc=1), file="ex_createDataset.h5", name="B", index=list(NULL,2))

h5dump("ex_createDataset.h5")

patperry/rhdf5 documentation built on May 24, 2019, 8:21 p.m.