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 Platforms currently supported include Linux 32 and 64-bit, SunOS 32 and
18 64-bit, Windows, FreeBSD, and Mac Intel. HDF allows self-definitions
19 of data content and easy extensibility for future enhancements or com‐
20 patibility with other standard formats. HDF includes Fortran and C
21 calling interfaces, and utilities for manipulating, viewing, and ana‐
22 lyzing data in HDF files. The HDF library contains interfaces for stor‐
23 ing and retrieving compressed or uncompressed 8-bit and 24-bit raster
24 images with palettes, n-Dimensional scientific datasets and binary
25 tables. An interface is also included that allows arbitrary grouping of
26 other HDF objects.
27 HDF Raster Images
30 HDF supports the storing of both 8-bit and 24-bit raster images. As
31 well as storing information about the dimensions and palette of a
32 raster image, HDF supports raster image compression. In previous ver‐
33 sions of HDF, Run-length encoding and Imcomp compression were both sup‐
34 ported. With HDF> 3.3 JPEG compression is also available.
35 HDF Scientific Data Sets
38 Scientific Data Sets (SDSs) are useful for storing n-Dimensional grid‐
39 ded data. The actual data in the dataset can be of any of the "stan‐
40 dard" number types: 8, 16 and 32bit signed and unsigned integers and 32
41 and 64bit floating point values. In addition, a certain amount of
42 meta-data can be stored with an SDS including:
43 o The coordinate system to use when interpreting or displaying the data.
45 o Scales to be used for each dimension.
46 o Labels for each dimension and the dataset as a whole.
47 o Units for each dimension and the data.
48 o The valid max and min values for the data.
49 o Calibration information for the data.
50 o Fill or missing value information.
51 o Ability of have more than one file open at a time.
52 o A more general framework for meta-data within the SDS data-model
53 (allowing 'name = value' styel meta-data).
54 o Support for an "unlimited dimension" in the SDS data-model, making
55 it possible to append planes to an array along one dimension.
56 HDF Annotations
58 Any object in an HDF file can have annotations associated with it.
59 There are a number of types of annotations:
60 o Labels are assumed to be short strings giving the "name" of a
62 data object.
63 o Descriptions are longer text segments that are useful for giving
64 more indepth information about a data object
65 o File annotations are assumed to apply to all of the objects in a
66 single file.
67 HDF Vset Interfaces
69 The Vset module provides interfaces to two basic HDF building blocks.
70 Vgroups are generic grouping elements allowing a user to associate
71 related objects within an HDF file. As Vgroups can contain other
72 Vgroups, it is possible to build a hierarchical file. Vdatas are data
73 structures made up of fields and records. Data is organized into
74 'fields' within each Vdata. Each field is identified by a unique
75 'fieldname'. The type of each field may be any of the basic number
76 types that HDF supports. Fields of different types may exist within
77 the same Vdata.
78 By combining Vdatas in Vgroups it is possible to represent higher level
80 data constructs: mesh data, multi-variate datasets, sparse matrices,
81 finite-element data, spreadsheets, splines, non-Cartesian coordinate
82 data, etc.
83 HDF > 3.3 and netCDF
86 HDF > 3.3 merges in the netCDF library produced by Unidata. The full
87 netCDF library is supported as is a new "multi-file" SDS interface.
88 Both of these interfaces can read old netCDF files and HDF files trans‐
89 parently.
90 EXAMPLES
94 All HDF routines require the header "hdf.h" to be included in the C
95 source file. If using the SDS routines the header "mfhdf.h" should be
96 included instead in in the C source file. Fortran programs should use
97 "dffunc.inc" and "hdf.inc".
98 To compile a program that makes HDF calls on most Unix platforms.
100 (FORTRAN):
102 {HDFLIBDIR}/bin/h4fc myprog.f
103 (C):
105 {HDFLIBDIR}/bin/h4cc myprog.c
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110 The HDF web site is located at http://www.hdfgroup.org/.
111 For the vast majority of users, the "HDF User's Guide" and "HDF Refer‐
113 ence Manual" should be sufficient.
114 These documents can be viewed or downloaded at
116 http://www.hdfgroup.org/products/hdf4/.
117
121 The HDF Group
122 1901 South First Street, Suite C-2
123 Champaign, IL 61820
124 USA
125 www.hdfgroup.org
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129 4.2.5
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132 Copyright by The HDF Group.
133 Copyright by the Board of Trustees of the University of Illinois.
134 All rights reserved.
136 This file is part of HDF. The full HDF copyright notice, including
138 terms governing use, modification, and redistribution, is contained in
139 the files COPYING and Copyright.html. COPYING can be found at the root
140 of the source code distribution tree; Copyright.html can be found at
141 http://hdfgroup.org/products/hdf4/doc/Copyright.html. If you do not
142 have access to either file, you may request a copy from
143 help@hdfgroup.org.
144
147 The HDF Group
148 Email: help@hdfgroup.org
149
152 /usr/local/lib/hdf/{libmfhdf.a,libdf.a,libjpeg.a,libz.a [,libsz.a]}
153 hdf libraries
154 /usr/local/bin Location of most hdf utilities
155 /usr/local/include/hdf Location of include file hdf.h, mfhdf.h,
156 and others
157THG HDF 4.2.5 February 2010 HDF(1)