hdf5 - Summary of MATLAB HDF5 capabilities

Description

MATLAB provides both high- and low-level access to Hierarchical Data Format (HDF5) files.

• High-level access functions make it easy to read a data set from an HDF5 file or write a variable from the MATLAB workspace into an HDF5 file.

• Low-level access functions provide direct access to the more than 300 functions in the HDF5 library.

Note   For information about MATLAB HDF4 capabilities, which is a completely separate and incompatible format, see hdf.

High-level Access Functions

These functions provide high-level access to HDF5 files:

• h5create — Create HDF5 data set

• h5disp — Display contents of HDF5 file

• h5info — Return information about HDF5 file

• h5read — Read data from HDF5 data set

• h5readatt — Read value of attribute from HDF5 group or data set

• h5write — Write data to HDF5 data set

• h5writeatt — Write data to HDF5 attribute

Note   To create or write to nonnumeric datasets or attributes, you must use the low-level interface.

Low-level Access Functions

MATLAB provides direct access to dozens of functions in the HDF5 library. Using these functions, you can read and write complex datatypes, use HDF5 data subsetting capabilities, and take advantage of other features present in the HDF5 library. To use these MATLAB functions, you must be familiar with HDF5 programming concepts and, when using the low-level functions, details about the functions in the library. To get this information, see http://www.hdfgroup.org.

The HDF5 library organizes the routines in the library into collections called interfaces. MATLAB organizes the corresponding MATLAB functions into packages that match these HDF5 library interfaces. For example, the MATLAB functions for the HDF5 Attribute Interface are in the H5A package.

The following table lists the HDF5 library interfaces alphabetically with their associated MATLAB package.

HDF5 Library Interface	MATLAB Package Name	Description
Library	H5	General-purpose functions for use with the entire HDF5 library, such as initialization
Attribute	H5A	Manipulate metadata associated with data sets or groups
Dataset	H5D	Manipulate multidimensional arrays of data elements, together with supporting metadata
Dimension Scale	H5DS	Manipulate dimension scale associated with dataset dimensions
Error	H5E	Handle errors
File	H5F	Access files
Group	H5G	Organize objects in a file; analogous to a folder structure
Identifier	H5I	Manipulate HDF5 object identifiers
Link	H5L	Manipulate links in a file
MATLAB	H5ML	MATLAB utility functions that are not part of the HDF5 library itself
Object	H5O	Manipulate objects in a file
Property	H5P	Manipulate object property lists
Reference	H5R	Manipulate HDF5 references, which are like UNIX links or Windows shortcuts
Dataspace	H5S	Define and work with data spaces, which describe the dimensionality of a data set
Datatype	H5T	Define the type of variable that is stored in a dataset
Filters and Compression	H5Z	Create inline data filters and data compression

In most cases, the syntax of the MATLAB function matches the syntax of the HDF5 library function. To get detailed information about the MATLAB syntax of an HDF5 library function, view the help for the individual MATLAB function, as follows:

help H5F.open

To view a list of all the MATLAB HDF5 functions in a particular interface, type:

help H5F

See Also

h5create | h5disp | h5info | h5read | h5readatt | h5write | h5writeatt | hdf

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