Provided by: libpdl-io-hdf5-perl_0.6501-2build2_amd64 
NAME
PDL::IO::HDF5::Dataset - PDL::IO::HDF5 Helper Object representing HDF5 datasets.
DESCRIPTION
This is a helper-object used by PDL::IO::HDF5 to interface with HDF5 format's dataset
objects. Information on the HDF5 Format can be found at the HDF Group's web site at
http://www.hdfgroup.org .
SYNOPSIS
See PDL::IO::HDF5
MEMBER DATA
ID
ID number given to the dataset by the HDF5 library
name
Name of the dataset.
parent
Ref to parent object (group) that owns this dateset.
fileObj
Ref to the PDL::IO::HDF5 object that owns this object.
METHODS
####---------------------------------------------------------
new
PDL::IO::HDF5::Dataset Constructor - creates new object
Usage:
This object will usually be created using the calling format detailed in the SYNOPSIS. The
following syntax is used by the PDL::IO::HDF5 object to build the object.
$a = new PDL::IO::HDF5:Dataset( name => $name, parent => $parent,
fileObj => $fileObj);
Args:
$name Name of the dataset
$parent Parent Object that owns this dataset
$fileObj PDL::HDF object that owns this dateset.
DESTROY
PDL::IO::HDF5::Dataset Destructor - Closes the dataset object
Usage:
No Usage. Automatically called
set
Write data to the HDF5 dataset
Usage:
$dataset->set($pdl, unlimited => 1); # Write the array data in the dataset
Options:
unlimited If present, the dataset is created with unlimited dimensions.
get
Get data from a HDF5 dataset to a PDL
Usage:
$pdl = $dataset->get; # Read the Array from the HDF5 dataset, create a PDL from it
# and put in $pdl
# Assuming $dataset is three dimensional
# with dimensions (20,100,90)
The get method can also be used to obtain particular slices or hyperslabs of the dataset
array. For example, if $dataset is three dimensional with dimensions (20,100,90) then we
could do:
$start=pdl([0,0,0]); # We begin the slice at the very beggining
$end=pdl([19,0,0]); # We take the first vector of the array,
$stride=pdl([2,1,1]); # taking only every two values of the vector
$pdl = $dataset->get($start,$end,[$stride]); # Read a slice or
# hyperslab from the HDF5 dataset.
# $start, $end and optionally $stride
# should be PDL vectors with length the
# number of dimensions of the dataset.
# $start gives the starting coordinates
# in the array.
# $end gives the ending coordinate
# in the array
# $stride gives the steps taken from one
# coordinate to the next of the slice
The mapping of HDF5 datatypes in the file to PDL datatypes in memory will be according to
the following table.
HDF5 File Type PDL Type
------------------------ -----------------
PDL::IO::HDF5::H5T_C_S1() => PDL::Char Object (Special Case for Char Strings)
PDL::IO::HDF5::H5T_STD_I8BE() => $PDL::Types::PDL_B
PDL::IO::HDF5::H5T_STD_I8LE() => $PDL::Types::PDL_B,
PDL::IO::HDF5::H5T_STD_U8BE() => $PDL::Types::PDL_S,
PDL::IO::HDF5::H5T_STD_U8LE() => $PDL::Types::PDL_S,
PDL::IO::HDF5::H5T_STD_I16BE() => $PDL::Types::PDL_S,
PDL::IO::HDF5::H5T_STD_I16LE() => $PDL::Types::PDL_S,
PDL::IO::HDF5::H5T_STD_U16BE() => $PDL::Types::PDL_L,
PDL::IO::HDF5::H5T_STD_U16LE() => $PDL::Types::PDL_L,
PDL::IO::HDF5::H5T_STD_I32BE() => $PDL::Types::PDL_L,
PDL::IO::HDF5::H5T_STD_I32LE() => $PDL::Types::PDL_L,
PDL::IO::HDF5::H5T_STD_U32LE() => $PDL::Types::PDL_LL,
PDL::IO::HDF5::H5T_STD_U32BE() => $PDL::Types::PDL_LL,
PDL::IO::HDF5::H5T_STD_I64LE() => $PDL::Types::PDL_LL,
PDL::IO::HDF5::H5T_STD_I64BE() => $PDL::Types::PDL_LL,
PDL::IO::HDF5::H5T_IEEE_F32BE()=> $PDL::Types::PDL_F,
PDL::IO::HDF5::H5T_IEEE_F32LE()=> $PDL::Types::PDL_F,
PDL::IO::HDF5::H5T_IEEE_F64BE()=> $PDL::Types::PDL_D,
PDL::IO::HDF5::H5T_IEEE_F64LE()=> $PDL::Types::PDL_D
For HDF5 File types not in this table, this method will attempt to map it to the default
PDL type PDL_D.
If the dataset being read is a scalar reference, the referenced dataset region will be
read instead.
Note:
Character arrays are returned as the special PDL::Char fixed-length string type. For
fixed-length HDF5 string arrays, this is a direct mapping to the PDL::Char datatype. For
HDF5 variable-length string arrays, the data is converted to a fixed-length character
array, with a string size equal to the maximum size of all the strings in the array.
dims
Get the dims for a HDF5 dataset. For example, a 3 x 4 array would return a perl array
(3,4);
Usage:
@pdl = $dataset->dims; # Get an array of dims.
attrSet
Set the value of an attribute(s)
Attribute types supported are null-terminated strings and PDL matrices
Usage:
$dataset->attrSet( 'attr1' => 'attr1Value',
'attr2' => 'attr2 value',
'attr3' => $pdl,
.
.
.
);
Returns undef on failure, 1 on success.
attrDel
Delete attribute(s)
Usage:
$dataset->attrDel( 'attr1',
'attr2',
.
.
.
);
Returns undef on failure, 1 on success.
attrs
Get a list of all attribute names associated with a dataset
Usage:
@attrs = $dataset->attrs;
attrGet
Get the value of an attribute(s)
Currently the attribute types supported are null-terminated strings and PDLs.
Usage:
my @attrs = $dataset->attrGet( 'attr1', 'attr2');
IDget
Returns the HDF5 library ID for this object
Usage:
my $ID = $dataSetObj->IDget;
nameGet
Returns the HDF5 Dataset Name for this object.
Usage:
my $name = $datasetObj->nameGet;