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Added html files with references to the fortran 90 files.
(under examples/)
This commit is contained in:
Barbara Jones
2001-03-19 09:26:47 -05:00
parent 380eb42bc5
commit f11cef2c56
30 changed files with 2967 additions and 3139 deletions
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doc/html/Tutor/crtatt.html
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@@ -36,160 +36,212 @@ width=78 height=27 alt="NCSA"><P></A>
<P>
Attributes are small datasets that can be used to describe the nature and/or
the intended usage of the object they are attached to. In this section, we
show how to create and read/write an attribute.
show how to create, read, and write an attribute.
<P>
<P>
<H3>Creating an attribute</H3>
<P>
Creating an attribute is similar to the creation of a dataset. To create an
attribute the application must specify the object which the attribute is
attached to, the data type and space of the attribute data and the creation
properties.
Creating an attribute is similar to creating a dataset. To create an
attribute, the application must specify the object which the attribute is
attached to, the datatype and dataspace of the attribute data,
and the attribute creation property list.
<P>
The steps to create an attribute are as follows:
<OL>
<LI> Obtain the object identifier that the attribute is to be attached to.
<LI> Define the characteristics of the attribute and specify creation
properties.
<LI> Define the characteristics of the attribute and specify the
attribute creation property list.
<UL>
<LI> Define the data type.
<LI> Define the datatype.
<LI> Define the dataspace.
<LI> Specify the creation properties.
<LI> Specify the attribute creation property list.
</UL>
<LI> Create the attribute.
<LI> Close the attribute and data type, dataspace, and creation property
list if necessary.
<LI> Close the attribute and datatype, dataspace, and
attribute creation property list, if necessary.
</OL>
<P>
To create an attribute, the calling program must contain the following calls:
To create and close an attribute, the calling program must use
<code>H5Acreate</code>/<code>h5acreate_f</code> and
<code>H5Aclose</code>/<code>h5aclose_f</code>. For example:
<P>
<I>C</I>:
<PRE>
attr_id = H5Acreate(loc_id, attr_name, type_id, space_id, create_plist);
H5Aclose(attr_id);
attr_id = H5Acreate (dset_id, attr_name, type_id, space_id, creation_prp);
status = H5Aclose (attr_id);
</PRE>
<I>FORTRAN</I>:
<PRE>
CALL h5acreate_f (dset_id, attr_nam, type_id, space_id, attr_id, &
hdferr, creation_prp=creat_plist_id)
<i>or</i>
CALL h5acreate_f (dset_id, attr_nam, type_id, space_id, attr_id, hdferr)
CALL h5aclose_f (attr_id, hdferr)
</PRE>
<H3>Reading/Writing an attribute</H3>
<P>
Attributes may only be read/written as an entire object. No partial I/O is
currently supported. Therefore, to perform I/O operations on an attribute, the
Attributes may only be read or written as an entire object; no partial I/O is
supported. Therefore, to perform I/O operations on an attribute, the
application needs only to specify the attribute and the attribute's memory
data type.
datatype.
<P>
The steps to read/write an attribute are as follows.
The steps to read or write an attribute are as follows.
<OL>
<LI> Obtain the attribute identifier.
<LI> Specify the attribute's memory data type.
<LI> Specify the attribute's memory datatype.
<LI> Perform the desired operation.
<LI> Close the memory data type if necessary.
<LI> Close the memory datatype if necessary.
</OL>
<P>
To read/write an attribute, the calling program must contain the following
calls:
To read and/or write an attribute, the calling program must contain the
<code>H5Aread</code>/<code>h5aread_f</code> and/or
<code>H5Awrite</code>/<code>h5awrite_f</code> routines. For example:
<P>
<I>C</I>:
<PRE>
status = H5Aread(attr_id, mem_type_id, buf);
status = H5Aread (attr_id, mem_type_id, buf);
status = H5Awrite (attr_id, mem_type_id, buf);
</PRE>
or
<I>FORTRAN</I>:
<PRE>
status = H5Awrite(attr_id, mem_type_id, buf);
CALL h5awrite_f (attr_id, mem_type_id, buf, hdferr)
CALL h5aread_f (attr_id, mem_type_id, buf, hdferr)
</PRE>
<P>
<H2> Programming Example</H2>
<A NAME="desc">
<H3><U>Description</U></H3>
This example shows how to create and write a dataset attribute.
It opens an existing file 'dset.h5', obtains the id of the dataset "/dset1",
It opens an existing file <code>dset.h5</code> in C
(<code>dsetf.h5</code> in FORTRAN),
obtains the identifier of the dataset <code>/dset</code>,
defines the attribute's dataspace, creates the dataset attribute, writes
the attribute, and then closes the attribute's dataspace, attribute, dataset,
and file. <BR>
[ <A HREF="examples/h5_crtatt.c">Download h5_crtatt.c</A> ]
<PRE>
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
<UL>
[ <A HREF="examples/h5_crtatt.c">C Example </A> ] - <code>h5_crtatt.c</code><BR>
[ <A HREF="examples/attrexample.f90">FORTRAN Example</A> ] - <code>attrexample.f90</code><BR>
[ <A HREF="examples/java/CreateAttribute.java">Java Example </A> ]
- <code>CreateAttribute.java</code><BR>
</UL>
#include &lt;hdf5.h&gt;
#define FILE "dset.h5"
<B>NOTE:</B> To download a tar file of the examples, including a Makefile,
please go to the <A HREF="references.html">References</A> page.
main() {
hid_t file_id, dataset_id, attribute_id, dataspace_id; /* identifiers
*/
hsize_t dims;
int attr_data[2];
herr_t status;
/* Initialize the attribute data. */
attr_data[0] = 100;
attr_data[1] = 200;
/* Open an existing file. */
file_id = H5Fopen(FILE, H5F_ACC_RDWR, H5P_DEFAULT);
/* Open an existing dataset. */
dataset_id = H5Dopen(file_id, "/dset");
/* Create the data space for the attribute. */
dims = 2;
dataspace_id = H5Screate_simple(1, &dims, NULL);
/* Create a dataset attribute. */
attribute_id = H5Acreate(dataset_id, "attr", H5T_STD_I32BE, dataspace_id, H5P_DEFAULT);
/* Write the attribute data. */
status = H5Awrite(attribute_id, H5T_NATIVE_INT, attr_data);
/* Close the attribute. */
status = H5Aclose(attribute_id);
/* Close the dataspace. */
status = H5Sclose(dataspace_id);
/* Close to the dataset. */
status = H5Dclose(dataset_id);
/* Close the file. */
status = H5Fclose(file_id);
}
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
</PRE>
<A NAME="rem">
<H3><U>Remarks</U></H3>
<UL>
<LI> H5Acreate creates an attribute which is attached to the object specified by
the first parameter, and returns an identifier.
<LI><code>H5Acreate</code>/<code>h5acreate_f</code> creates an attribute
which is attached to the object specified by the first parameter,
and returns an identifier.
<P>
<I>C</I>:
<PRE>
hid_t H5Acreate (hid_t loc_id, const char *name, hid_t type_id,
hid_t space_id, hid_t create_plist)
hid_t H5Acreate (hid_t obj_id, const char *name, hid_t type_id,
hid_t space_id, hid_t creation_prp)
</PRE>
<I>FORTRAN</I>:
<PRE>
h5acreate_f (obj_id, name, type_id, space_id, attr_id, &
hdferr, creation_prp)
obj_id INTEGER(HID_T)
name CHARACTER(LEN=*)
type_id INTEGER(HID_T)
space_id INTEGER(HID_T)
attr_id INTEGER(HID_T)
hdferr INTEGER
(Possible values: 0 on success and -1 on failure)
creation_prp INTEGER(HID_T), OPTIONAL
</PRE>
<UL>
<LI> The first parameter is the identifier of the object which the attribute is
attached to.
<LI> The second parameter is the name of the attribute to create.
<LI> The third parameter is the identifier of the attribute's datatype.
<LI> The fourth parameter is the identifier of the attribute's dataspace.
<LI> The last parameter is the identifier of the creation property list.
H5P_DEFAULT specifies the default creation property list.
<LI> The <I>obj_id</I> parameter is the identifier of the object that
the attribute is attached to.
<P>
<LI> The <I>name</I> parameter is the name of the attribute to create.
<P>
<LI> The <I>type_id</I> parameter is the identifier of the
attribute's datatype.
<P>
<LI> The <I>space_id</I> parameter is the identifier of the attribute's
dataspace.
<P>
<LI> The <I>creation_prp</I> parameter is the creation property list
identifier.
<code>H5P_DEFAULT</code> in C (<code>H5P_DEFAULT_F</code> in FORTRAN)
specifies the default creation property list.
This parameter is optional in FORTRAN; when it is omitted,
the default creation property list is used.
<P>
<LI> In FORTRAN, the return code for this call is returned in <I>hdferr</I>:
0 if successful, -1 if not. The attribute identifier is returned
in <I>attr_id</I>. In C, the function returns the
attribute identifier if successful and a negative value if not.
</UL>
<P>
<LI> H5Awrite writes the entire attribute, and returns the status of the write.
<LI><code>H5Awrite</code>/<code>h5awrite_f</code> writes the entire attribute,
and returns the status of the write.
<P>
<I>C</I>:
<PRE>
herr_t H5Awrite (hid_t attr_id, hid_t mem_type_id, void *buf)
</PRE>
<I>FORTRAN</I>:
<PRE>
h5awrite_f (attr_id, mem_type_id, buf, hdferr)
attr_id INTEGER(HID_T)
memtype_id INTEGER(HID_T)
buf TYPE(VOID)
hdferr INTEGER
(Possible values: 0 on success and -1 on failure)
</PRE>
<UL>
<LI> The first parameter is the identifier of the attribute to write.
<LI> The second parameter is the identifier of the attribute's memory datatype.
<LI> The last parameter is the data buffer.
<LI> The <I>attr_id</I> parameter is the identifier of the attribute
to write.
<P>
<LI> The <I>mem_type_id</I> parameter is the identifier of the
attribute's memory datatype.
<P>
<LI> The <I>buf</I> parameter is the data buffer to write out.
<P>
<LI>In C, this function returns a non-negative value if successful and
a negative value, otherwise. In FORTRAN, the return value is in the
<I>hdferr</I> parameter: 0 if successful, -1 otherwise.
</UL>
<P>
<LI> When an attribute is no longer accessed by a program, H5Aclose must be called
to release the attribute from use. This call is mandatory.
<PRE>
<LI> When an attribute is no longer accessed by a program,
<code>H5Aclose</code>/<code>h5aclose_f</code> must be called
to release the attribute from use.
The C routine returns a non-negative value if successful;
otherwise it returns a negative value.
In FORTRAN, the return value is in the <I>hdferr</I> parameter:
0 if successful, -1 otherwise.
<P>
<I>C</I>:
<pre>
herr_t H5Aclose (hid_t attr_id)
</PRE>
</pre>
<I>FORTRAN</I>:
<pre>
h5aclose_f (attr_id, hdferr)
attr_id INTEGER(HID_T)
hdferr INTEGER
(Possible values: 0 on success and -1 on failure)
</pre>
<ul>
<li> An <code>H5Aclose</code>/<code>h5aclose_f</code> call is mandatory.
</ul>
</UL>
@@ -197,35 +249,61 @@ main() {
<A NAME="fc">
<H3><U>File Contents</U></H3>
<P>
The contents of 'dset.h5' and the attribute definition are given in the
following:
The contents of <code>dset.h5</code> (<code>dsetf.h5</code> for FORTRAN) and the
attribute definition are shown below:
<P>
<B>Fig. 7.1</B> &nbsp; <I>'dset.h5' in DDL</I>
<B>Fig. 7.1a</B> &nbsp; <I><code>dset.h5</code> in DDL</I>
<PRE>
HDF5 "dset.h5" {
GROUP "/" {
DATASET "dset" {
DATATYPE { H5T_STD_I32BE }
DATASPACE { SIMPLE ( 4, 6 ) / ( 4, 6 ) }
DATA {
1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18,
19, 20, 21, 22, 23, 24
}
ATTRIBUTE "attr" {
DATATYPE { H5T_STD_I32BE }
DATASPACE { SIMPLE ( 2 ) / ( 2 ) }
DATA {
100, 200
}
}
HDF5 "dset.h5" {
GROUP "/" {
DATASET "dset" {
DATATYPE { H5T_STD_I32BE }
DATASPACE { SIMPLE ( 4, 6 ) / ( 4, 6 ) }
DATA {
1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18,
19, 20, 21, 22, 23, 24
}
ATTRIBUTE "attr" {
DATATYPE { H5T_STD_I32BE }
DATASPACE { SIMPLE ( 2 ) / ( 2 ) }
DATA {
100, 200
}
}
}
}
}
}
</PRE>
<B>Fig. 7.1b</B> &nbsp; <I><code>dsetf.h5</code> in DDL</I>
<PRE>
HDF5 "dsetf.h5" {
GROUP "/" {
DATASET "dset" {
DATATYPE { H5T_STD_I32BE }
DATASPACE { SIMPLE ( 6, 4 ) / ( 6, 4 ) }
DATA {
1, 7, 13, 19,
2, 8, 14, 20,
3, 9, 15, 21,
4, 10, 16, 22,
5, 11, 17, 23,
6, 12, 18, 24
}
ATTRIBUTE "attr" {
DATATYPE { H5T_STD_I32BE }
DATASPACE { SIMPLE ( 2 ) / ( 2 ) }
DATA {
100, 200
}
}
}
}
}
</PRE>
<A NAME="ddl">
@@ -254,7 +332,8 @@ following:
<!-- <A HREF="helpdesk.mail.html"> -->
<A HREF="mailto:hdfhelp@ncsa.uiuc.edu">
hdfhelp@ncsa.uiuc.edu</A>
<BR> <H6>Last Modified: August 27, 1999</H6><BR>
<br>
<BR> <H6>Last Modified: March 9, 2001</H6><BR>
<!-- modified by Barbara Jones - bljones@ncsa.uiuc.edu -->
</FONT>
<BR>