From 0f7e7766509bdf92eda32e08f50dc8197a231710 Mon Sep 17 00:00:00 2001 From: Frank Baker Date: Fri, 2 Jul 2004 17:27:00 -0500 Subject: [svn-r8797] Purpose: To more carefully describe the -- behavior of H5Pset_external -- appropriate usage of H5Pset_shuffle Description: H5Pset_external Add notes that first H5Pset_external call sets the dataset as EXTERNAL and identifies the first file in the series of external files that will hold the dataset; subsequent calls identify additional files; all external files must be declared before the dataset is created; and the library will create files that don't yet exist on the system at the time that H5Dwrite is called to write data to that file. H5Pset_shuffle Added notes regarding usage of H5Pset_shuffle in concert with a compression filter. And, as always, a few copy edits. --- doc/html/RM_H5P.html | 47 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 14 deletions(-) diff --git a/doc/html/RM_H5P.html b/doc/html/RM_H5P.html index 1b15b8a..9897793 100644 --- a/doc/html/RM_H5P.html +++ b/doc/html/RM_H5P.html @@ -2328,7 +2328,6 @@ END SUBROUTINE h5pget_class_parent_f include the following: 
            H5FD_CORE
-           H5FD_DPSS
            H5FD_FAMILY
            H5FD_GASS
            H5FD_LOG
@@ -6428,35 +6427,49 @@ END SUBROUTINE h5pset_edc_check_f
   
Purpose:
     
Adds an external file to the list of external files.
   
Description:
-    
H5Pset_external adds an external file to the 
-        list of external files. 
+    
The first call to H5Pset_external sets the 
+	external storage property in the property list,
+	thus designating that the dataset will be stored in 
+	one or more non-HDF5 file(s) external to the HDF5 file.
+	This call also adds the file name as the 
+	first file in the list of external files.
+	Subsequent calls to the function add the named file as
+	the next file in the list.
         

-        If a dataset is split across multiple files then the files
+        If a dataset is split across multiple files, then the files
         should be defined in order. The total size of the dataset is
         the sum of the size arguments for all the external files.  If
         the total size is larger than the size of a dataset then the
         dataset can be extended (provided the data space also allows
         the extending).
         

-        The size argument specifies number of bytes reserved 
+        The size argument specifies the number of bytes reserved 
         for data in the external file.
         If  size is set to H5F_UNLIMITED, the 
-        external file can be of unlimited size and no more files can be added to
-        the external files list.
+        external file can be of unlimited size and no more files can be added 
+        to the external files list.
+        

+	All of the external files for a given dataset must be 
+	specified with H5Pset_external 
+	before H5Dcreate is called to create 
+	the dataset. 
+	If one these files does not exist on the system when 
+	H5Dwrite is called to write data to it, 
+        the library will create the file.
   
Parameters:
     
    
-		    
+            
-		    
+            
-		    
+            
-		    
+            
    
         
    hid_t plisthid_t plist
             IN: Identifier of a dataset creation property list.
    
         
    const char *name    const char *name    
             IN: Name of an external file.
    
         
    off_t offsetoff_t offset
             IN: Offset, in bytes, from the beginning of the file
                 to the location in the file where the data starts.
    
         
    hsize_t sizehsize_t size
             IN: Number of bytes reserved in the file for the data.
    
     

   
Returns:
@@ -8694,8 +8707,14 @@ END SUBROUTINE h5pset_preserve_f
 	closely related to each other and putting them together 
         can increase the compression ratio.
 	

-	This filter is designed to be used in combination with 
-	a compression filter.
+	As  implied above, the primary value of the shuffle filter 
+        lies in its coordinated use with a compression filter; 
+	it does not provide data compression when used alone. 
+        When the shuffle filter is applied to a dataset 
+        immediately prior to the use of a compression filter, 
+        the compression ratio achieved is often superior to that
+        achieved by the use of a compression filter without 
+        the shuffle filter.
   
Parameters:
     
    
@@ -9683,7 +9702,7 @@ And in this document, the
 Describes HDF5 Release 1.7, the unreleased development branch; working toward HDF5 Release 1.8.0
 
  
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