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Intro
======
H5.intro.html
Major rewrite to Groups section. New Example 7 (groups).
Added TOC and requisite links.
Numbered sections.
Labelled figures and centered those that were not.
Fixed table formatting.
===========
User Guide
===========
H5.user.html
Linked in Chunking.html.
Linked in References.html.
Linked in DDL.html.
Chunking.html
Minor edits.
DDL.html
References.html
New documents.
Datatypes.html
Added "R Reference" to base name description and
"H5T_STD_ROBJ -- Reference to an entire object
in a file" to list of datatype names.
Files.html
H5Fflush
Added scope parameter.
Groups.html
Removed references to "current working group."
Removed H5Gpush, H5Gpop, and H5Gset functions.
Removed note that H5Glink and H5Gunlink were not implemented.
=================
Reference Manual
=================
RM_*.html and Tools.html
Updated Reference Manual internal cross-linking (the link
banner at the top and bottom of each page).
Changed
Returns SUCCEED (0) if successful;
otherwise FAIL (-1).
to read
Returns a non-negative value if successful;
otherwise returns a negative value.
and several derived changes where circumstances differred
only slightly.
Minor copy edits throughout.
RM_H5.html
Corrected H5open "Purpose" statement.
RM_H5A.html
Changed H5Aget_name return type to hssize_t.
RM_H5F.html
H5Fflush
Added scope parameter.
Added H5Freopen.
RM_H5Front.html
Reordered listing of interfaces to alphabetical order (H5,
H5A, H5D, ...)
Added H5I, H5R, and H5RA.
RM_H5G.html
H5Gopen
Edited "Description."
H5Gget_objinfo
Added named datatype to list of valid values for loc_id.
RM_H5I.html Identifier Interface
New section.
RM_H5P.html
Added H5Pset_fill_value and H5Pget_fill_value.
Several minor copy edits.
RM_H5R.html Reference Interface
New section.
H5RA.html
Essentially a new section. It was in the tree previously,
but it did not actually have content.
RM_H5S.html
Changed H5Sget_select_npoints return type to hssize_t.
Tools.html
Updated h5dump documentation.
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<HTML>
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<HEAD>
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<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
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<TITLE>The Data Space Interface (H5S)</TITLE>
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</HEAD>
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<BODY>
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<H1>
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The Dataspace Interface (H5S)</H1>
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<H2>
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1. Introduction</H2>
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The dataspace interface (H5S) provides a mechanism to describe the positions
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of the elements of a dataset and is designed in such a way as to allow
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new features to be easily added without disrupting applications that use
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the dataspace interface. A dataset (defined with the dataset interface) is
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composed of a collection of raw data points of homogeneous type, defined in the
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datatype (H5T) interface, organized according to the dataspace with this
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interface.
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<P>A dataspace describes the locations that dataset elements are located at.
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A dataspace is either a regular N-dimensional array of data points,
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called a <I>simple</I> dataspace, or a more general collection of data
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points organized in another manner, called a <I>complex</I> dataspace.
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A <I>scalar</I> dataspace is a special case of the <I>simple</I> data
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space and is defined to be a 0-dimensional single data point in size. Currently
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only <I>scalar</I> and <I>simple</I> dataspaces are supported with this version
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of the H5S interface.
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<I>Complex</I> dataspaces will be defined and implemented in a future
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version. <I>Complex</I> dataspaces are intended to be used for such structures
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which are awkward to express in <I>simple</I> dataspaces, such as irregularly
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gridded data or adaptive mesh refinement data. This interface provides
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functions to set and query properties of a dataspace.
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<P>Operations on a dataspace include defining or extending the extent of
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the dataspace, selecting portions of the dataspace for I/O and storing the
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dataspaces in the file. The extent of a dataspace is the range of coordinates
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over which dataset elements are defined and stored. Dataspace selections are
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subsets of the extent (up to the entire extent) which are selected for some
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operation.
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<P>For example, a 2-dimensional dataspace with an extent of 10 by 10 may have
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the following very simple selection:
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<br><br><center>
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<table border cellpadding=4>
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<tr align=center>
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<th > </th> <th >0</th> <th >1</th> <th >2</th> <th >3</th> <th >4</th> <th >5</th> <th >6</th> <th >7</th> <th >8</th> <th >9</th>
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<tr align=center>
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<th>0</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>1</th>
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<td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>2</th>
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<td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>3</th>
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<td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>4</th>
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<td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>5</th>
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<td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>6</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>7</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>8</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>9</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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</table>
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<br><strong>Example 1: Contiguous rectangular selection</strong>
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</center>
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<br>Or, a more complex selection may be defined:
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<br><br><center>
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<table border cellpadding=4>
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<tr align=center>
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<th > </th> <th >0</th> <th >1</th> <th >2</th> <th >3</th> <th >4</th> <th >5</th> <th >6</th> <th >7</th> <th >8</th> <th >9</th>
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<tr align=center>
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<th>0</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>1</th>
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<td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>2</th>
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<td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>3</th>
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<td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>4</th>
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<td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>5</th>
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<td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>6</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>7</th>
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<td>-</td><td>-</td><td>X</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>8</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>9</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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</table>
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<br><strong>Example 2: Non-contiguous selection</strong>
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</center>
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<P>Selections within dataspaces have an offset within the extent which is used
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to locate the selection within the extent of the dataspace. Selection offsets
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default to 0 in each dimension, but may be changed to move the selection within
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a dataspace. In example 2 above, if the offset was changed to 1,1, the selection
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would look like this:
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<br><br><center>
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<table border cellpadding=4>
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<tr align=center>
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<th > </th> <th >0</th> <th >1</th> <th >2</th> <th >3</th> <th >4</th> <th >5</th> <th >6</th> <th >7</th> <th >8</th> <th >9</th>
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<tr align=center>
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<th>0</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>1</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>2</th>
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<td>-</td><td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td>
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<tr align=center>
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<th>3</th>
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<td>-</td><td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>4</th>
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<td>-</td><td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td>
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<tr align=center>
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<th>5</th>
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<td>-</td><td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>6</th>
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<td>-</td><td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td>
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<tr align=center>
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<th>7</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>8</th>
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<td>-</td><td>-</td><td>-</td><td>X</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td>
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<tr align=center>
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<th>9</th>
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<td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>
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</table>
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<br><strong>Example 3: Non-contiguous selection with 1,1 offset</strong>
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</center>
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<P>Selections also have an linearization ordering of the points selected
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(defaulting to "C" order, ie. last dimension changing fastest). The
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linearization order may be specified for each point or it may be chosen by
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the axis of the dataspace. For example, with the default "C" ordering,
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example 1's selected points are iterated through in this order: (1,1), (2,1),
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(3,1), (1,2), (2,2), etc. With "FORTRAN" ordering, example 1's selected points
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would be iterated through in this order: (1,1), (1,2), (1,3), (1,4), (1,5),
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(2,1), (2,2), etc.
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<P>A dataspace may be stored in the file as a permanent object, to allow many
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datasets to use a commonly defined dataspace. Dataspaces with extendable
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extents (ie. unlimited dimensions) are not able to be stored as permanent
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dataspaces.
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<P>Dataspaces may be created using an existing permanent dataspace as a
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container to locate the new dataspace within. These dataspaces are complete
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dataspaces and may be used to define datasets. A dataspaces with a "parent"
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can be queried to determine the parent dataspace and the location within the
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parent. These dataspaces must currently be the same number of dimensions as
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the parent dataspace.
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<H2> 2. General Dataspace Operations</H2>
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The functions defined in this section operate on dataspaces as a whole.
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New dataspaces can be created from scratch or copied from existing data
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spaces. When a dataspace is no longer needed its resources should be released
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by calling <TT>H5Sclose()</TT>.
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<DL>
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<DT>
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<TT>hid_t H5Screate(H5S_class_t <I>type</I>)</TT></DT>
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<DD>
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This function creates a new dataspace of a particular <I>type</I>. The
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types currently supported are H5S_SCALAR, H5S_SIMPLE, or H5S_NONE, although
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others are planned to be added later. The H5S_NONE dataspace can only hold a
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selection, not an extent.
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</DD>
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<DT>
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<TT>hid_t H5Sopen(hid_t <I>location</I>, const char *<I>name</I>)</TT></DT>
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<DD>
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This function opens a permanent dataspace for use in an application.
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The <I>location</I> argument is a file or group ID and <I>name</I> is
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an absolute or relative path to the permanent dataspace. The dataspace ID which
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is returned is a handle to a permanent dataspace which can't be modified.
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</DD>
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<DT>
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<TT>hid_t H5Scopy (hid_t <I>space</I>)</TT></DT>
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<DD>
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This function creates a new dataspace which is an exact copy of the
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dataspace <I>space</I>.
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</DD>
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<DT>
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<TT>hid_t H5Ssubspace (hid_t <I>space</I>)</TT></DT>
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<DD>
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This function uses the currently defined selection and offset in <I>space</I>
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to create a dataspace which is located within <I>space</I>. The <I>space</I>
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dataspace must be a sharable dataspace located in the file, not a dataspace for
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a dataset. The relationship of the new dataspace within the existing dataspace
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is preserved when the new dataspace is used to create datasets. Currently,
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only subspaces which are equivalent to simple dataspaces (ie. rectangular
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contiguous areas) are allowed. A subspace is not "simplified" or reduced in
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the number of dimensions used if the selection is "flat" in one dimension, they
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always have the same number of dimensions as their parent dataspace.
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</DD>
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<DT>
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<TT>herr_t H5Scommit (hid_t <I>location</I>, const char *<I>name</I>, hid_t <I>space</I>)</TT></DT>
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<DD>
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The dataspaces specified with <I>space</I> is stored in the file specified
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by <I>location</I>. <I>Location</I> may be either a file or group handle
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and <I>name</I> is an absolute or relative path to the location to store the
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dataspace. After this call, the dataspace is permanent and can't be modified.
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</DD>
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<DT>
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<TT>herr_t H5Sclose (hid_t <I>space</I>)</TT></DT>
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<DD>
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Releases resources associated with a dataspace. Subsequent use of the
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dataspace identifier after this call is undefined.
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</DD>
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<DT>
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<TT>H5S_class_t H5Sextent_class (hid_t <I>space</I>)</TT></DT>
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<DD>
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Query a dataspace to determine the current class of a dataspace. The value
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which is returned is one of: H5S_SCALAR, H5S_SIMPLE on success or
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H5S_NO_CLASS on failure.
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</DD>
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</DL>
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<H2> 3. Dataspace Extent Operations</H2>
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These functions operate on the extent portion of a dataspace.
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<DL>
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<DT>
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<TT>herr_t H5Sset_extent_simple (hid_t <I>space</I>, int <I>rank</I>, const hsize_t
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*<I>current_size</I>, const hsize_t *<I>maximum_size</I>)</TT></DT>
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<DD>
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Sets or resets the size of an existing dataspace, where <I>rank</I> is
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the dimensionality, or number of dimensions, of the dataspace.
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<I>current_size</I> is an array of size <I>rank</I> which contains the new size
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of each dimension in the dataspace. <I>maximum_size</I> is an array of size
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<I>rank</I> which contains the maximum size of each dimension in the dataspace.
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Any previous extent is removed from the dataspace, the dataspace type is set to
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H5S_SIMPLE and the extent is set as specified.
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</DD>
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<DT>
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<TT>herr_t H5Sset_extent_none (hid_t <I>space</I>)</TT></DT>
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<DD>
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Removes the extent from a dataspace and sets the type to H5S_NONE.
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</DD>
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<DT>
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<TT>herr_t H5Sextent_copy (hid_t <I>dest_space</I>,
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hid_t <I>source_space</I>)</TT></DT>
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<DD>
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Copies the extent from <I>source_space</I> to <I>dest_space</I>, which may
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change the type of the dataspace. Returns non-negative on success, negative on
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failure.
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</DD>
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<DT>
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<TT>hsize_t H5Sget_simple_extent_npoints (hid_t <I>space</I>)</TT></DT>
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<DD>
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This function determines the number of elements in a dataspace. For example, a
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simple 3-dimensional dataspace with dimensions 2, 3 and 4 would have 24
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elements.
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Returns the number of elements in the dataspace, negative on failure.
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</DD>
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<DT>
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<TT>int H5Sget_simple_extent_ndims (hid_t <I>space</I>)</TT></DT>
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<DD>
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This function determines the dimensionality (or rank) of a dataspace.
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Returns the number of dimensions in the dataspace, negative on failure.
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</DD>
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<DT>
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<TT>herr_t H5Sget_simple_extent_dims (hid_t <I>space</I>, hsize_t *<I>dims</I>,
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hsize_t *<I>max</I>)</TT></DT>
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<DD>
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The function retrieves the size of the extent of the dataspace <I>space</I> by
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placing the size of each dimension in the array <I>dims</I>. Also retrieves
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the size of the maximum extent of the dataspace, placing the results in
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<I>max</I>.
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Returns non-negative on success, negative on failure.
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</DD>
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</DL>
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<H2> 4. Dataspace Selection Operations</H2>
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Selections are maintained separately from extents in dataspaces and operations
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on the selection of a dataspace do not affect the extent of the dataspace.
|
|
Selections are independent of extent type and the boundaries of selections are
|
|
reconciled with the extent at the time of the data transfer. Selection offsets
|
|
apply a selection to a location within an extent, allowing the same selection
|
|
to be moved within the extent without requiring a new selection to be specified.
|
|
Offsets default to 0 when the dataspace is created. Offsets are applied when
|
|
an I/O transfer is performed (and checked during calls to H5Sselect_valid).
|
|
Selections have an iteration order for the points selected, which can be any
|
|
permutation of the dimensions involved (defaulting to 'C' array order) or a
|
|
specific order for the selected points, for selections composed of single array
|
|
elements with H5Sselect_elements. Selections can also be copied or combined
|
|
together in various ways with H5Sselect_op. Further methods of selecting
|
|
portions of a dataspace may be added in the future.
|
|
|
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<DL>
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<DT>
|
|
<TT>herr_t H5Sselect_hyperslab (hid_t <I>space</I>, h5s_selopt_t <I>op</I>,
|
|
const hssize_t * <I>start</I>, const hsize_t * <I>stride</I>,
|
|
const hsize_t * <I>count</I>, const hsize_t * <I>block</I>)</TT></DT>
|
|
|
|
<DD>
|
|
This function selects a hyperslab region to add to the current selected region
|
|
for the <I>space</I> dataspace. The <I>start</I>, <I>stride</I>, <I>count</I>
|
|
and <I>block</I> arrays must be the same size as the rank of the dataspace.
|
|
The selection operator <I>op</I> determines how the new selection is to be
|
|
combined with the already existing selection for the dataspace. Currently,
|
|
only the H5S_SELECT_SET operator is supported, which replaces the existing
|
|
selection with the parameters from this call. Overlapping blocks are not
|
|
supported with the H5S_SELECT_SET operator.
|
|
<P>The <I>start</I> array determines the starting coordinates of the hyperslab
|
|
to select. The <I>stride</I> array chooses array locations from the dataspace
|
|
with each value in the <I>stride</I> array determining how many elements to move
|
|
in each dimension. Setting a value in the <I>stride</I> array to 1 moves to
|
|
each element in that dimension of the dataspace, setting a value of 2 in a
|
|
location in the <I>stride</I> array moves to every other element in that
|
|
dimension of the dataspace. In other words, the <I>stride</I> determines the
|
|
number of elements to move from the <I>start</I> location in each dimension.
|
|
Stride values of 0 are not allowed. If the <I>stride</I> parameter is <TT>NULL</TT>,
|
|
a contiguous hyperslab is selected (as if each value in the <I>stride</I> array
|
|
was set to all 1's). The <I>count</I> array determines how many blocks to
|
|
select from the dataspace, in each dimension. The <I>block</I> array determines
|
|
the size of the element block selected from the dataspace. If the <I>block</I>
|
|
parameter is set to <TT>NULL</TT>, the block size defaults to a single element
|
|
in each dimension (as if the <I>block</I> array was set to all 1's).
|
|
<P>For example, in a 2-dimensional dataspace, setting <I>start</I> to [1,1],
|
|
<I>stride</I> to [4,4], <I>count</I> to [3,7] and <I>block</I> to [2,2] selects
|
|
21 2x2 blocks of array elements starting with location (1,1) and selecting
|
|
blocks at locations (1,1), (5,1), (9,1), (1,5), (5,5), etc.
|
|
<P>Regions selected with this function call default to 'C' order iteration when
|
|
I/O is performed.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>herr_t H5Sselect_elements (hid_t <I>space</I>, h5s_selopt_t <I>op</I>,
|
|
const size_t <I>num_elements</I>, const hssize_t *<I>coord</I>[])</TT></DT>
|
|
|
|
<DD>
|
|
This function selects array elements to be included in the selection for the
|
|
<I>space</I> dataspace. The number of elements selected must be set with the
|
|
<I>num_elements</I>. The <I>coord</I> array is a two-dimensional array of size
|
|
<dataspace rank> by <<I>num_elements</I>> in size (ie. a list of
|
|
coordinates in the array). The order of the element coordinates in the
|
|
<I>coord</I> array also specifies the order that the array elements are
|
|
iterated through when I/O is performed. Duplicate coordinate locations are not
|
|
checked for.
|
|
|
|
<P>The selection operator <I>op</I> determines how the new selection is to be
|
|
combined with the already existing selection for the dataspace. Currently,
|
|
only the H5S_SELECT_SET operator is supported, which replaces the existing
|
|
selection with the parameters from this call. When operators other than
|
|
H5S_SELECT_SET are used to combine a new selection with an existing selection,
|
|
the selection ordering is reset to 'C' array ordering.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>herr_t H5Sselect_all (hid_t <I>space</I>)</TT></DT>
|
|
|
|
<DD>
|
|
This function selects the special H5S_SELECT_ALL region for the <I>space</I>
|
|
dataspace. H5S_SELECT_ALL selects the entire dataspace for any dataspace is is
|
|
applied to.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>herr_t H5Sselect_none (hid_t <I>space</I>)</TT></DT>
|
|
|
|
<DD>
|
|
This function resets the selection region for the <I>space</I>
|
|
dataspace not to include any elements.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>herr_t H5Sselect_op (hid_t <I>space1</I>, h5s_selopt_t <I>op</I>,
|
|
hid_t <I>space2</I>)</TT></DT>
|
|
|
|
<DD>
|
|
Uses <I>space2</I> to perform an operation on <I>space1</I>. The valid
|
|
operations for <I>op</I> are:
|
|
<DL>
|
|
<DT>H5S_SELECT_COPY
|
|
<DD>Copies the selection from <I>space2</I> into <I>space1</I>, removing any
|
|
previously defined selection for <I>space1</I>. The selection order
|
|
and offset are also copied to <I>space1</I>
|
|
<DT>H5S_SELECT_UNION
|
|
<DD>Performs a set union of the selection of the dataspace <I>space2</I>
|
|
with the selection from the dataspace <I>space1</I>, with the result
|
|
being stored in <I>space1</I>. The selection order for <I>space1</I> is
|
|
reset to 'C' order.
|
|
<DT>H5S_SELECT_INTERSECT
|
|
<DD>Performs an set intersection of the selection from <I>space2</I> with
|
|
<I>space1</I>, with the result being stored in <I>space1</I>. The
|
|
selection order for <I>space1</I> is reset to 'C' order.
|
|
<DT>H5S_SELECT_DIFFERENCE
|
|
<DD>Performs a set difference of the selection from <I>space2</I> with
|
|
<I>space1</I>, with the result being stored in <I>space1</I>. The
|
|
selection order for <I>space1</I> is reset to 'C' order.
|
|
</DL>
|
|
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>herr_t H5Sselect_order (hid_t <I>space</I>,
|
|
hsize_t <I>perm_vector</I>[])</TT></DT>
|
|
|
|
<DD>
|
|
This function selects the order to iterate through the dimensions of a dataspace
|
|
when performing I/O on a selection. If a specific order has already been
|
|
selected for the selection with H5Sselect_elements, this function will remove
|
|
it and use a dimension oriented ordering on the selected elements. The elements
|
|
of the <I>perm_vector</I> array must be unique and between 0 and the rank of the
|
|
dataspace, minus 1. The order of the elements in <I>perm_vector</I> specify
|
|
the order to iterate through the selection for each dimension of the dataspace.
|
|
To iterate through a 3-dimensional dataspace selection in 'C' order, specify
|
|
the elements of the <I>perm_vector</I> as [0, 1, 2], for FORTRAN order they
|
|
would be [2, 1, 0]. Other orderings, such as [1, 2, 0] are also possible, but
|
|
may execute slower.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>hbool_t H5Sselect_valid (hid_t <I>space</I>)</TT></DT>
|
|
|
|
<DD>
|
|
This function verifies that the selection for a dataspace is within the extent
|
|
of the dataspace, if the currently set offset for the dataspace is used.
|
|
Returns TRUE if the selection is contained within the extent, FALSE if it
|
|
is not contained within the extent and FAIL on error conditions (such as if
|
|
the selection or extent is not defined).
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>hsize_t H5Sget_select_npoints (hid_t <I>space</I>)</TT></DT>
|
|
|
|
<DD>
|
|
This function determines the number of elements in the current selection
|
|
of a dataspace.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>herr_t H5Soffset_simple (hid_t <I>space</I>, const hssize_t *
|
|
<I>offset</I>)</TT></DT>
|
|
|
|
<DD>
|
|
Sets the offset of a simple dataspace <I>space</I>. The <I>offset</I> array
|
|
must be the same number of elements as the number of dimensions for the
|
|
dataspace. If the <I>offset</I> array is set to <TT>NULL</TT>, the offset
|
|
for the dataspace is reset to 0.
|
|
</DD>
|
|
|
|
</DL>
|
|
|
|
<H2> 5. Misc. Dataspace Operations</H2>
|
|
|
|
<DL>
|
|
|
|
<DT>
|
|
<TT>herr_t H5Slock (hid_t <I>space</I>)</TT></DT>
|
|
|
|
<DD>
|
|
Locks the dataspace so that it cannot be modified or closed. When the library
|
|
exits, the dataspace will be unlocked and closed.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>hid_t H5Screate_simple(int <I>rank</I>, const hsize_t *<I>current_size</I>,
|
|
const hsize_t *<I>maximum_size</I>)</TT></DT>
|
|
|
|
<DD>
|
|
This function is a "convenience" wrapper to create a simple dataspace
|
|
and set it's extent in one call. It is equivalent to calling H5Screate
|
|
and H5Sset_extent_simple() in two steps.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>int H5Sis_subspace(hid_t <I>space</I>)</TT></DT>
|
|
|
|
<DD>
|
|
This function returns positive if <I>space</I> is located within another
|
|
dataspace, zero if it is not, and negative on a failure.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>char *H5Ssubspace_name(hid_t <I>space</I>)</TT></DT>
|
|
|
|
<DD>
|
|
This function returns the name of the named dataspace that <I>space</I>
|
|
is located within. If <I>space</I> is not located within another dataspace,
|
|
or an error occurs, NULL is returned. The application is responsible for
|
|
freeing the string returned.
|
|
</DD>
|
|
|
|
<DT>
|
|
<TT>herr_t H5Ssubspace_location(hid_t <I>space</I>, hsize_t *<I>loc</I>)</TT></DT>
|
|
|
|
<DD>
|
|
If <I>space</I> is located within another dataspace, this function puts
|
|
the location of the origin of <I>space</I> in the <I>loc</I> array. The <I>loc</I>
|
|
array must be at least as large as the number of dimensions of <I>space</I>.
|
|
If <I>space</I> is not located within another dataspace
|
|
or an error occurs, a negative value is returned, otherwise a non-negative value
|
|
is returned.
|
|
</DD>
|
|
|
|
</DL>
|
|
|
|
<HR>
|
|
<!--
|
|
<ADDRESS>
|
|
<A HREF="mailto:matzke@llnl.gov">Robb Matzke</A></ADDRESS>
|
|
|
|
<ADDRESS>
|
|
<A HREF="mailto:koziol@ncsa.uiuc.edu">Quincey Koziol</A></ADDRESS>
|
|
|
|
<BR>
|
|
-->
|
|
<!-- Created: Thu Dec 4 14:57:32 EST 1997 --><!-- hhmts start -->
|
|
<!--
|
|
Last modified: Thu May 28 15:12:04 EST 1998
|
|
-->
|
|
<!-- hhmts end -->
|
|
|
|
<hr>
|
|
<address>
|
|
<a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a>
|
|
|
|
<br>
|
|
Last modified: 26 October 1998
|
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|
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