2 =====================================================================
3 libtime: support processing of sampling parameters
4 =====================================================================
6 This software is part of the project Seitosh. See README.1st in the root
7 directory of the collection or https://git.scc.kit.edu/Seitosh/Seitosh for
8 general installation instructions.
10 libtime is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 =====================================================================
26 This library supports numerical operations for dates and times with integer
27 precision down to microseconds. Time comes in two different flavours:
29 1. absolute time (like today at 10 o'clock) as supported by
30 libtime::TAbsoluteTime in the C++ version of the library
31 2. relative times (like the time span between now and christmas) as
32 supported by libtime::TRelativeTime in the C++ version of the library.
33 For time differences (libtime::TRelativeTime) only positive values are
34 accepted. Accidentally the library appears to handle negative value too.
35 However, since the underlying Fortran code is designed to handle positive
36 values only, functions should throw an exception upon negative values
39 The modules in the library support operations like:
41 1. calculate the number of samples in a time window
42 2. calculate the expected time and date for the first sample in
44 3. calculate the time gap between two data blocks
45 4. calculate the the index of the sample nearest to a given time
46 5. calculate the residual time between a given time and the nearest sample
48 The library provides interfaces in Fortran, C, C++. Unfortunately handling of
49 leapseconds is not yet supported.
51 =====================================================================
54 Call 'make all' to install C and C++ header files, compile the binary version
55 of the library and create documentation files. Header files wil be installed
56 in a directory adressed by the environment variable ${LOCINCLUDEDIR}. Binary
57 libraries will be placed in ${LOCLIBDIR} and doxygen documentation output will
58 be written to subdirectories of ${TF_WWWBASEDIR}..
62 This is a base library. It depends only on common system libraries.
63 To compile the code, current versions of a C, a C++, and a Fortran compiler
64 are required as well as GNU make and doxygen (for documentation files).
68 Four binary libraries are provided:
69 libtime.a: pure FORTRAN libtime
70 libtime_trad.a: traditional libtime (obsolete)
71 libctime.a: pure C libtime
72 libtime++.a: C++ classlib
73 libtime++.so: C++ classlib (shared library)
77 For details on the C++ and C implementation of the library please check the
78 doxygen documentation being created from the source code.
80 An ASCII text version to the function interfaces in the Fortran 77, C, and C++
81 versions of the library, see the file libtime.doc which is created during
86 Several examples and test programs are provided in subdirectory test.
88 =====================================================================
89 A short description of the Fortran implementation of this library:
90 ------------------------------------------------------------------
92 libtime (C) by Thomas Forbriger (IfG Stuttgart) 1997
94 A FORTRAN library to manipulate absolute and relative data times
95 with a large dynamic range.
97 ---------------------------------------------------------------------
99 time format declaration
101 the absolute time value is stored in an integer array:
112 A year of value 0 will indicate that this is a relative time. This
113 affects the routines time_norm and time_getdate and time_sprint.
114 Notice that the routine time_fullyear will NOT be affected by this
115 declaration and will set a year of value 0 to 2000.
117 The best way to be aware of absolute/relative time confusion is
118 to finish every manual setting of absolute times by a call to
119 time_finish and to keep the year value fo relative times zero
122 Absolute times are only accepted from year 100 on. Users must expect
123 some routines to set year values below 100 to the range of 1970 to 2069.
125 Only positive time values will be accepted. Therefore routines like
126 time_sub will return only the absolute value of the difference.
128 ---------------------------------------------------------------------
130 subroutines and what they do
132 time_libversion returns library version V1.0
133 time_isleapyear returns leapyear flag V1.0
134 time_fullyear returns full year value V1.0
135 time_setdoy returns day of year V1.0
136 time_getdate get date from doy V1.0
137 time_sprint print time to character array V1.0
138 time_clear clears a time record to zero V1.0
139 time_norm set all field to correct value range V1.0
140 time_add add two time records V1.0
141 time_sub calculate difference V1.0
142 time_copy copy a time record V1.0
143 time_finish finish setting of absolute time value V1.0
144 time_compare compare two time values V1.0
145 time_mul multiply relative time by integer n V1.0
146 time_div divide relative time by integer n V1.0
147 time_nfit find number of samples fiitng in time V1.0
148 time_read extra time from a timestring V1.03
149 time_info print description of time format
151 ---- END OF README ----
1.8.14