1HDF(1) General Commands Manual HDF(1)
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6 hdf - Hierarchical Data Format library
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9 -lmfhdf -ldf -ljpeg -lz [ -lsz ]
10 {HDFLIBDIR}/libmfhdf.a {HDFLIBDIR}/libdf.a {JPEGLIBDIR}/libjpeg.a
11 {GZIPLIBDIR}/libz.a [{SZIPLIBDIR}/libsz.a]
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15 HDF is a multi-object file format that facilitates the transfer of var‐
16 ious types of scientific data between machines and operating systems.
17 See http://www.hdfgroup.org/release4/platforms.html for a list of plat‐
18 forms currently supported.
19 HDF allows self-definitions of data content and easy extensibility for
21 future enhancements or compatibility with other standard formats. HDF
22 includes Fortran and C calling interfaces, and utilities for manipulat‐
23 ing, viewing, and analyzing data in HDF files. The HDF library contains
24 interfaces for storing and retrieving compressed or uncompressed 8-bit
25 and 24-bit raster images with palettes, n-Dimensional scientific
26 datasets and binary tables. An interface is also included that allows
27 arbitrary grouping of other HDF objects.
28 HDF Raster Images
31 HDF supports the storing of both 8-bit and 24-bit raster images.
32 Beside storing information about the dimensions and palette of a raster
33 image, HDF supports raster image compression. In previous versions of
34 HDF (DF interfaces,) Run-length encoding and Imcomp compression were
35 both supported. The currently supported compression methods include
36 simple RLE, N-bit, Skipping huffman, Gzip, Szip, and JPEG. Although no
37 longer support Imcomp compression, the library can read images with
38 Imcomp compression.
39 HDF Scientific Data Sets
42 Scientific Data Sets (SDSs) are useful for storing n-Dimensional grid‐
43 ded data. The actual data in the dataset can be of any of the "stan‐
44 dard" number types: 8, 16 and 32bit signed and unsigned integers and 32
45 and 64bit floating point values. In addition, a certain amount of
46 meta-data can be stored with an SDS including:
47 o The coordinate system to use when interpreting or displaying the data.
49 o Scales to be used for each dimension.
50 o Labels for each dimension and the dataset as a whole.
51 o Units for each dimension and the data.
52 o The valid max and min values for the data.
53 o Calibration information for the data.
54 o Fill or missing value information.
55 o Ability of having more than one file open at a time.
56 o A more general framework for meta-data within the SDS data-model
57 (allowing 'name = value' style meta-data.)
58 o Support for an "unlimited dimension" in the SDS data-model, making
59 it possible to append planes to an array along one dimension.
60 HDF Annotations
62 Any object in an HDF file can have annotations associated with it.
63 There are a number of types of annotations:
64 o Labels are assumed to be short strings giving the "name" of a
66 data object.
67 o Descriptions are longer text segments that are useful for giving
68 more indepth information about a data object
69 o File annotations are assumed to apply to all of the objects in a
70 single file.
71 HDF Vset Interfaces
73 The Vset module provides interfaces to two basic HDF building blocks.
74 Vgroups are generic grouping elements allowing a user to associate
75 related objects within an HDF file. As Vgroups can contain other
76 Vgroups, it is possible to build a hierarchical file. Vdatas are data
77 structures made up of fields and records. Data is organized into
78 "fields" within each Vdata. Each field is identified by a unique
79 "fieldname". The type of each field may be any of the basic number
80 types that HDF supports. Fields of different types may exist within
81 the same Vdata.
82 By combining Vdatas in Vgroups it is possible to represent higher level
84 data constructs: mesh data, multi-variate datasets, sparse matrices,
85 finite-element data, spreadsheets, splines, non-Cartesian coordinate
86 data, etc.
87 HDF and netCDF
90 Starting with HDF version 3.3, netCDF v.2.3.2 of Unidata is supported
91 with the SD multifile interface. SD and netCDF interfaces can read both
92 netCDF files and multi-dimensional arrays (SDS) stored in the HDF4
93 files transparently. For more information, see Chapter 3, "Scientific
94 Data Sets", of the HDF User's Guide.
95 To disable netCDF interfaces in the HDF library, configure the library
97 using --disable-netcdf flag and rebuild it.
98 EXAMPLES
101 All HDF routines require the header "hdf.h" to be included in the C
102 source file, unless if the SD routines are used, then the header
103 "mfhdf.h" should be included instead.
104 Fortran programs should use "dffunc.inc" for all interfaces,
106 "mffunc.inc" for the SD interfaces, and "hdf.inc" for non-SD inter‐
107 faces.
108 To compile a program that makes HDF calls on most Unix platforms.
110 (FORTRAN):
112 {HDFLIBDIR}/bin/h4fc myprog.f
113 (C):
115 {HDFLIBDIR}/bin/h4cc myprog.c
116
120 The HDF web site is located at http://www.hdfgroup.org/.
121 For the vast majority of users, the "HDF User's Guide" and "HDF Refer‐
123 ence Manual" should be sufficient.
124 These documents can be viewed or downloaded at
126 http://www.hdfgroup.org/products/hdf4/.
127
131 The HDF Group
132 1800 South Oak Street, Suite 203
133 Champaign, IL 61820
134 USA
135 www.hdfgroup.org
136
139 4.2.15
140
142 Copyright by The HDF Group.
143 Copyright by the Board of Trustees of the University of Illinois.
144 All rights reserved.
146 This file is part of HDF. The full HDF copyright notice, including
148 terms governing use, modification, and redistribution, is contained in
149 the COPYING file, which can be found at the root of the source code
150 distribution tree, or in https://support.hdf‐
151 group.org/ftp/HDF/releases/.
152 If you do not have access to either file, you may request a copy from
153 help@hdfgroup.org.
154
157 The HDF Group
158 Email: help@hdfgroup.org
159
162 /usr/local/lib/hdf/{libmfhdf.a,libdf.a,libjpeg.a,libz.a [,libsz.a]}
163 hdf libraries
164 /usr/local/bin Location of most hdf utilities
165 /usr/local/include/hdf Location of include file hdf.h, mfhdf.h,
166 and others
167THG HDF 4.2.15 November 2019 HDF(1)