hdf5/doc/html/RM_H5Z.html
Frank Baker 82fb21b613 [svn-r985] Checking in changes from "HDF5 Release 1.0" CVS branch that have not yet
been checked into "HDF5 Development" branch.

General
=======
	Various "copy edit" types of repairs.
	Revisions to document cross-linking.
	Added structural links tying all docs together (banners
	   at top and bottom of documents, similar to Reference Manual
	   banners of the Beta release).
	Set background color to white in all documents.

NCSAfooterlogo.gif
hdf2.jpg
	New image files to make the documents more self-contained
	(i.e., to prevent loading images from NCSA and HDF home servers).

index.html
	Redesigned to isolate links external to the installation
	in a single location.


Intro to HDF5
=============
H5.intro.html
	Fixed banner linking Intro to other docs.
	Set all URLs to be relative within the distribution; nothing
	   points back to the HDF server.
	Updates to "Limits of the Current Release" and "Changes in
	   the Current Release."


HDF5 User's Guide
=================
	Changed several User Guide section titles such that all
	   sections that are primarily about a particular interface
	   are now titled in the format "The xxxxx Interface (H5x)".

H5.user.html
	Commented out links to developer docs since they are marked
	   in MANIFEST as not being for distribution in the release.
	Removed 2nd and 3rd indices from page.
	Changed "freeform" lists of sections (TOCs) to aligned tables.

Datatypes.html
	Removed the sentence "I'm deferring definition until later
	   since they're probably not as important as the other data
	   types." from Section 3.3, "Properties of Date and Time
	   Atomic Types."
	Added info regarding 'char' versus 'string' datatypes.  Added
	   as Section 3.7, "Character and String Datatype Issues."

References.html
	Commented out substantial material (at end of document) from
	   References planning document that is not appropriate for
 	   the User Guide but that is worth keeping around.

Groups.html
	Final edits from elimination of "current working group."


HDF5 Reference Manual
=====================
	Removed "Draft" from the <title>__</title> lines.

RM_H5Front.html
	Removed 2nd and 3rd indices from page.
	Changed "freeform" lists of sections (TOCs) to aligned tables.

RM_H5F.html
RM_H5P.html
	Add file mounting information.
1998-12-21 17:52:56 -05:00

163 lines
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HTML

<html>
<head><title>
HDF5/H5Z API Specification
</title></head>
<body bgcolor="#FFFFFF">
<hr>
<center>
<table border=0 width=98%>
<tr><td valign=top align=left>
<a href="H5.intro.html">Introduction to HDF5</a>&nbsp;<br>
<a href="H5.user.html">HDF5 User Guide</a>&nbsp;<br>
<a href="index.html">Other HDF5 documents and links</a>&nbsp;<br>
<!--
<a href="Glossary.html">Glossary</a><br>
-->
</td>
<td valign=top align=right>
And in this document, the
<a href="RM_H5Front.html">HDF5 Reference Manual</a>&nbsp;&nbsp;
<br>
<a href="RM_H5.html">H5</a>&nbsp;&nbsp;
<a href="RM_H5A.html">H5A</a>&nbsp;&nbsp;
<a href="RM_H5D.html">H5D</a>&nbsp;&nbsp;
<a href="RM_H5E.html">H5E</a>&nbsp;&nbsp;
<a href="RM_H5F.html">H5F</a>&nbsp;&nbsp;
<a href="RM_H5G.html">H5G</a>&nbsp;&nbsp;
<a href="RM_H5I.html">H5I</a>&nbsp;&nbsp;
<br>
<a href="RM_H5P.html">H5P</a>&nbsp;&nbsp;
<a href="RM_H5R.html">H5R</a>&nbsp;&nbsp;
<a href="RM_H5RA.html">H5RA</a>&nbsp;&nbsp;
<a href="RM_H5S.html">H5S</a>&nbsp;&nbsp;
<a href="RM_H5T.html">H5T</a>&nbsp;&nbsp;
H5Z&nbsp;&nbsp;
<a href="Tools.html">Tools</a>&nbsp;&nbsp;
</td></tr>
</table>
</center>
<hr>
<center>
<h1>H5Z: Compression Interface</h1>
</center>
<h2>Compression API Functions</h2>
This function enable the user to configure a new compression
method for the local environment.
<table border=0>
<tr><td valign=top>
<ul>
<li><a href="#Compression-Register">H5Zregister</a>
</ul>
</td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top>
<ul>
&nbsp;
</ul>
</td></tr>
</table>
<p>
HDF5 supports compression of raw data by compression methods
built into the library or defined by an application.
A compression method is associated with a dataset when the dataset is
created and is applied independently to each storage chunk of the dataset.
The dataset must use the <code>H5D_CHUNKED</code> storage layout.
<p>
The HDF5 library does not support compression for contiguous datasets
because of the difficulty of implementing random access for partial I/O.
Compact dataset compression is not supported because it would not produce
significant results.
<p>
See <a href="Compression.html"><cite>Compression</cite></a> in the
<cite>HDF5 User's Guide</cite> for further information.
<hr>
<dl>
<dt><strong>Name:</strong> <a name="Compression-Register">H5Zregister</a>
<dt><strong>Signature:</strong>
<dd><em>herr_t</em> <code>H5Zregister</code>(<em>H5Z_method_t</em> <code>method</code>,
<em>const char *</em><code>name</code>,
<em>H5Z_func_t</em><code>cfunc</code>,
<em>H5Z_func_t</em> <code>ufunc</code>
)
<dt><strong>Purpose:</strong>
<dd> Registers new compression and uncompression functions for a
method specified by a method number.
<dt><strong>Description:</strong>
<dd><code>H5Zregister</code> registers new compression and uncompression
functions for a method specified by a method number, <code>method</code>.
<code>name</code> is used for debugging and may be the null pointer.
Either or both of <code>cfunc</code> (the compression function) and
<code>ufunc</code> (the uncompression method) may be null pointers.
<p>
The statistics associated with a method number are not reset
by this function; they accumulate over the life of the library.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>H5Z_method_t</em> <code>method</code>
<dd>Number specifying compression method.
<dt><em>const char *</em><code>name</code>
<dd>Name associated with the method number.
<dt><em>H5Z_func_t</em> <code>cfunc</code>
<dd>Compression method.
<dt><em>H5Z_func_t</em> <code>ufunc</code>
<dd>Uncompression method.
</dl>
<dt><strong>Returns:</strong>
<dd>Returns a non-negative value if successful;
otherwise returns a negative value.
</dl>
<hr>
<center>
<table border=0 width=98%>
<tr><td valign=top align=left>
<a href="H5.intro.html">Introduction to HDF5</a>&nbsp;<br>
<a href="H5.user.html">HDF5 User Guide</a>&nbsp;<br>
<a href="index.html">Other HDF5 documents and links</a>&nbsp;<br>
<!--
<a href="Glossary.html">Glossary</a><br>
-->
</td>
<td valign=top align=right>
And in this document, the
<a href="RM_H5Front.html">HDF5 Reference Manual</a>&nbsp;&nbsp;
<br>
<a href="RM_H5.html">H5</a>&nbsp;&nbsp;
<a href="RM_H5A.html">H5A</a>&nbsp;&nbsp;
<a href="RM_H5D.html">H5D</a>&nbsp;&nbsp;
<a href="RM_H5E.html">H5E</a>&nbsp;&nbsp;
<a href="RM_H5F.html">H5F</a>&nbsp;&nbsp;
<a href="RM_H5G.html">H5G</a>&nbsp;&nbsp;
<a href="RM_H5I.html">H5I</a>&nbsp;&nbsp;
<br>
<a href="RM_H5P.html">H5P</a>&nbsp;&nbsp;
<a href="RM_H5R.html">H5R</a>&nbsp;&nbsp;
<a href="RM_H5RA.html">H5RA</a>&nbsp;&nbsp;
<a href="RM_H5S.html">H5S</a>&nbsp;&nbsp;
<a href="RM_H5T.html">H5T</a>&nbsp;&nbsp;
H5Z&nbsp;&nbsp;
<a href="Tools.html">Tools</a>&nbsp;&nbsp;
</td></tr>
</table>
</center>
<hr>
<address>
<a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a>
<br>
Last modified: 30 October 1998
</body>
</html>