NCSA HDF Specifications

Table of Contents

National Center for Supercomputing Applications

March 1989










	Table of Contents




Introduction
Overview  v
What Is HDF  vi
Chapter 1	The Basic Structure of HDF Files
Chapter Overview  1.1
File Header  1.1
Data Object  1.1
Physical Organization of HDF Files  1.4
Chapter 2	The NCSA HDF General Purpose Interface
Chapter Overview  2.1
Introduction  2.1
Opening and Closing Files  2.1
Finding Tags, Refs, and Element Lengths  2.1
Reading and Writing Entire Data Elements  2.2
Reading and Writing Part of a Data Element  2.2
Manipulating Data Descriptors  2.2

Chapter 3	Sets and Groups
Chapter Overview  3.1
Sets  3.1
Groups  3.2
Raster Image Sets  3.4
Scientific Data Sets  3.6
Chapter 4	HDF Conventions
Chapter Overview  4.1
Byte Order  4.1
Naming and Assigning Tags 4.1 
Using Reference Numbers to Organize Data Objects  4.2
Multiple References and File Compaction  4.3
Chapter 5	Other Formats
Chapter Overview  5.1
File Formats  5.1
Appendix A	NCSA HDF Tags
Appendix B	Header Files
Glossary

Figures and Tables
Figure 1	Raster Image Sets in an HDF File  	vi
Figure 1.1	Three Data Objects  1.1
Figure 1.2	A Data Descriptor  1.2
Figure 1.3	Model of a Data Descriptor Block  1.3
Figure 1.4	Example Data Descriptor Block  1.4
Figure 1.5	Physical Representation of Data 	Objects  1.5
Figure 3.1	Physical Organization of Example 	RIG Groupings  3.3
Figure B.1	FORTRAN Header File:  dfF.h  
	B.2ÐB3
Figure B.2	C Header File:  df.h  B.4ÐB.8

Table 1.1	Parts of a Data Descriptor  1.2
Table 1.2	Summary of the Relationships 	among Parts of an HDF File  1.4
Table 1.3	Sample Data Objects in an HDF File  	1.5
Table 3.1	Tags for Raster-8 Sets  3.4
Table 3.2	Tags for Raster Image Sets  3.5
Table 3.3	Additional Tags for Raster Image 	Sets  3.6
Table 3.4	Required Tags for Scientific Data 	Sets  3.6
Table 3.5	Optional Tags for Scientific Data 	Sets  3.7
Table 4.1	Sample Grouping of Data Objects in 	an HDF File  4.1
Table A.1	Number Type Fields  A.3
Table A.2	Number Type Values  A.4
Table A.3	Possible Machine Types  A.5
Table A.4	Possible Tag Types in an RIG  A.7
Table A.5	Dimension Record Fields  A.8
Table A.6	Color Correction Field Types  A.9
Table A.7	Color Format String Values  A.9
Table A.8	Possible Tag Types in an SDG  A.12
Table A.9	Scientific Data Dimension Record 	Fields  A.12