From bug-octave-request at bevo dot che dot wisc dot edu Sun Dec 3 15:37:36 2000 Subject: possible error in time, ctime and related routines From: Gerard van Dijnsen To: bug-octave at bevo dot che dot wisc dot edu Date: Sun, 03 Dec 2000 22:37:07 -0100 Bug report for Octave 2.0.16 configured for i386-redhat-linux-gnu Description: ----------- I believe the output of time and ctime and related routines might be offset by one hour. I am not too sure of myself, because the same bug seems to exist in my linux distribution's date command. Perhaps I am one who is entirely wrong here... If that is the case, sorry. Repeat-By: --------- The easiest way to reproduce this error is by evaluating: ctime(0) This should yield a date of 1-1-1970, 0:00:00, while instead it yields: 31-12-1969, 23:00:00! It's not critical, but I thought you'd like to know! Fix: --- I have added one of my own functions here. I have not extensively tested it, but it seems to work ok. It converts dates in the format produced by the clock function to seconds after the epoch. I believe it works ok, though it seems to be one hour off compared to octave (and the linux date command), which is how I found the bug (if it is one). Anyways, feel free to use the code if you find it useful! The function name sucks, so please think of somthing more appropriate :-) function [t]=clck2sec(tv) # # This function calculates the seconds from the epoch from a date given # in the time vector tv in the format produced by the clock function. # tv may contain multiple rows with date information, which will result in # a single column t, containing the corresponding seconds from the epoch for # every row. # Catching of some obvious errors: if size(tv,2)<6, error('Seems not a valid timevector or timematrix!') endif if ( sum(tv(:,1)<1970) | sum(tv(:,2)<1 | tv(:,2)>12) | sum(tv(:,3)<1 | tv(:,3)>31) | sum(tv(:,4)<0 | tv(:,4)>23) | sum(tv(:,5)<0 | tv(:,5)>59) | sum(tv(:,6)<0 | tv(:,6)>60) ), error('Timevector or matrix contains illegal values!') endif # Are we dealing with a leapyear? isleap= (mod(tv(:,1),4)==0 & mod(tv(:,1),100)~=0) | (mod(tv(:,1),400)==0); hsecs=60*60; dsecs=24*hsecs; ysecs=365*dsecs; t=0; #Almost unreadable calculation, but it is FAST. t=(tv(:,1)-1970).*ysecs+fix((tv(:,1)-1-1968)./4).*dsecs-... (fix(tv(:,1)./100)-19).*dsecs+(fix(tv(:,1)./400)-4).*dsecs; t=t+(tv(:,2)>1).*31.*dsecs+(tv(:,2)>2).*28.*dsecs+isleap.*dsecs+... (tv(:,2)>3).*31.*dsecs+(tv(:,2)>4).*30.*dsecs+(tv(:,2)>5).*31.*dsecs+... (tv(:,2)>6).*30.*dsecs+(tv(:,2)>7).*31.*dsecs+(tv(:,2)>8).*31.*dsecs+... (tv(:,2)>9).*30.*dsecs+(tv(:,2)>10).*31.*dsecs+(tv(:,2)>11).*30.*dsecs; t=t+(tv(:,3)-1).*dsecs+tv(:,4).*hsecs+tv(:,5).*60+tv(:,6); endfunction Configuration (please do not edit this section): ----------------------------------------------- uname output: Linux delgul.gvd.dhs.org 2.2.16-22 #1 Tue Aug 22 16:49:06 EDT 2000 i686 unknown configure opts: i386-redhat-linux --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib +--libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/usr/com --mandir=/usr/share/man --infodir=/usr/share/info --enable-dl --enable-shared --enable-rpath --enable-lite-kernel +--enable-picky-flags --enable-static=no Fortran compiler: g77 FFLAGS: -O2 -march=i386 -mcpu=i686 F2C: F2CFLAGS: FLIBS: -lg2c -lm -L/usr/lib/gcc-lib/i386-redhat-linux/2.96 -L/usr/lib/gcc-lib/i386-redhat-linux/2.96/../../.. -lm CPPFLAGS: INCFLAGS: -I/usr/include -I/usr/include/octave-2.0.16 C compiler: gcc, version 2.96 20000731 (experimental) CFLAGS: -DHAVE_CONFIG_H -mieee-fp -O2 -march=i386 -mcpu=i686 CPICFLAG: -fPIC C++ compiler: egcs++, version 2.91.66 19990314/Linux (egcs-1.1.2 release) CXXFLAGS: -DHAVE_CONFIG_H -mieee-fp -fno-rtti -fno-exceptions -fno-implicit-templates -O2 -march=i386 -mcpu=i686 CXXPICFLAG: -fPIC LDFLAGS: -g LIBFLAGS: -L/usr/lib/octave-2.0.16 RLD_FLAG: -Xlinker -rpath -Xlinker /usr/lib/octave-2.0.16 TERMLIBS: -lncurses LIBS: LEXLIB: LIBPLPLOT: LIBDLFCN: DEFS: -DOCTAVE_SOURCE=1 -DSEPCHAR=':' -DSEPCHAR_STR=":" -DUSE_READLINE=1 -D__NO_MATH_INLINES=1 -DCXX_NEW_FRIEND_TEMPLATE_DECL=1 -DHAVE_LIBM=1 -DF77_APPEND_UNDERSCORE=1 -DOCTAVE_LITE=1 -DSIZEOF_SHORT=2 -DSIZEOF_INT=4 -DSIZEOF_LONG=4 -DHAVE_ALLOCA_H=1 -DHAVE_ALLOCA=1 -DNPOS=string::npos -DSTDC_HEADERS=1 -DHAVE_DIRENT_H=1 -DTIME_WITH_SYS_TIME=1 -DHAVE_SYS_WAIT_H=1 -DHAVE_ASSERT_H=1 -DHAVE_CURSES_H=1 -DHAVE_DLFCN_H=1 -DHAVE_FCNTL_H=1 -DHAVE_FLOAT_H=1 -DHAVE_FNMATCH_H=1 -DHAVE_GLOB_H=1 -DHAVE_GRP_H=1 -DHAVE_LIMITS_H=1 -DHAVE_MEMORY_H=1 -DHAVE_NCURSES_H=1 -DHAVE_POLL_H=1 -DHAVE_PWD_H=1 -DHAVE_SGTTY_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_SYS_IOCTL_H=1 -DHAVE_SYS_PARAM_H=1 -DHAVE_SYS_POLL_H=1 -DHAVE_SYS_RESOURCE_H=1 -DHAVE_SYS_SELECT_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_SYS_TIME_H=1 -DHAVE_SYS_TIMES_H=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_UTSNAME_H=1 -DHAVE_TERMCAP_H=1 -DHAVE_TERMIO_H=1 -DHAVE_TERMIOS_H=1 -DHAVE_UNISTD_H=1 -DHAVE_VARARGS_H=1 -DHAVE_ATEXIT=1 -DHAVE_BCOPY=1 -DHAVE_BZERO=1 -DHAVE_DUP2=1 -DHAVE_ENDGRENT=1 -DHAVE_ENDPWENT=1 -DHAVE_EXECVP=1 -DHAVE_FCNTL=1 -DHAVE_FORK=1 -DHAVE_GETCWD=1 -DHAVE_GETEGID=1 -DHAVE_GETEUID=1 -DHAVE_GETGID=1 -DHAVE_GETGRENT=1 -DHAVE_GETGRGID=1 -DHAVE_GETGRNAM=1 -DHAVE_GETHOSTNAME=1 -DHAVE_GETPGRP=1 -DHAVE_GETPID=1 -DHAVE_GETPPID=1 -DHAVE_GETPWENT=1 -DHAVE_GETPWNAM=1 -DHAVE_GETPWUID=1 -DHAVE_GETTIMEOFDAY=1 -DHAVE_GETUID=1 -DHAVE_GETWD=1 -DHAVE_LSTAT=1 -DHAVE_MEMMOVE=1 -DHAVE_MKDIR=1 -DHAVE_MKFIFO=1 -DHAVE_ON_EXIT=1 -DHAVE_PIPE=1 -DHAVE_PUTENV=1 -DHAVE_RENAME=1 -DHAVE_RINDEX=1 -DHAVE_RMDIR=1 -DHAVE_SELECT=1 -DHAVE_SETGRENT=1 -DHAVE_SETPWENT=1 -DHAVE_SETVBUF=1 -DHAVE_SIGACTION=1 -DHAVE_SIGPENDING=1 -DHAVE_SIGPROCMASK=1 -DHAVE_SIGSUSPEND=1 -DHAVE_STAT=1 -DHAVE_STRCASECMP=1 -DHAVE_STRDUP=1 -DHAVE_STRERROR=1 -DHAVE_STRNCASECMP=1 -DHAVE_TEMPNAM=1 -DHAVE_UMASK=1 -DHAVE_UNLINK=1 -DHAVE_USLEEP=1 -DHAVE_VFPRINTF=1 -DHAVE_VSPRINTF=1 -DHAVE_WAITPID=1 -DHAVE_PROGRAM_INVOCATION_NAME=1 -DHAVE_LIBDL=1 -DHAVE_DLOPEN=1 -DHAVE_DLSYM=1 -DHAVE_DLERROR=1 -DHAVE_DLCLOSE=1 -DWITH_DL=1 -DWITH_DYNAMIC_LINKING=1 -DHAVE_FINITE=1 -DHAVE_ISNAN=1 -DHAVE_ISINF=1 -DHAVE_ACOSH=1 -DHAVE_ASINH=1 -DHAVE_ATANH=1 -DHAVE_ERF=1 -DHAVE_ERFC=1 -DHAVE_ST_BLKSIZE=1 -DHAVE_ST_BLOCKS=1 -DHAVE_ST_RDEV=1 -DHAVE_TM_ZONE=1 -DHAVE_GR_PASSWD=1 -DEXCEPTION_IN_MATH=1 -DRETSIGTYPE=void -DSYS_SIGLIST_DECLARED=1 -DHAVE_SYS_SIGLIST=1 -DHAVE_POSIX_SIGNALS=1 -DHAVE_GETRUSAGE=1 -DHAVE_TIMES=1 -DGNUPLOT_HAS_MULTIPLOT=1 -DGNUPLOT_HAS_FRAMES=1 User-preferences (please do not edit this section): -------------------------------------------------- EDITOR = "emacs" EXEC_PATH = ":/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin:/home/gerard/bin" IMAGEPATH = ".:/usr/share/octave/2.0.16/imagelib//" INFO_FILE = "/usr/share/info/octave.info" INFO_PROGRAM = "info" LOADPATH = ":~/octave:~/octave/lib" PAGER = "less -e -P'-- less ?pB(%pB\\%):--. (f)orward, (b)ack, (q)uit$'" PS1 = ">> " PS2 = PS4 = "+ " auto_unload_dot_oct_files = 0 automatic_replot = 1 beep_on_error = 1 completion_append_char = " " default_eval_print_flag = 1 # default_global_variable_value = default_return_value = [] default_save_format = "ascii" define_all_return_values = 0 do_fortran_indexing = 1 echo_executing_commands = 0 empty_list_elements_ok = 1 fixed_point_format = 0 gnuplot_binary = "gnuplot" gnuplot_has_frames = 1 gnuplot_has_multiplot = 1 history_file = "/home/gerard/.octave_hist" history_size = 1024 ignore_function_time_stamp = "system" implicit_num_to_str_ok = 0 implicit_str_to_num_ok = 0 initialize_global_variables = 0 max_recursion_depth = 256 ok_to_lose_imaginary_part = "warn" output_max_field_width = 10 output_precision = 5 page_output_immediately = 0 page_screen_output = 1 prefer_column_vectors = 1 prefer_zero_on print_answer_id_name = 1 print_empty_dimensions = 0 propagate_empty_matrices = 1 resize_on_range_error = 1 return_last_computed_value = 0 save_precision = 15 saving_history = 1 silent_functions = 0 split_long_rows = 1 string_fill_char = " " struct_levels_to_print = 2 suppress_verbose_help_message = 1 treat_neg_dim_as_zero = 0 warn_assign_as_truth_value = 1 warn_comma_in_global_decl = 1 warn_divide_by_zero = 1 warn_function_name_clash = 1 warn_missing_semicolon = 0 warn_reload_forces_clear = 1 warn_variable_switch_label = 0 whitespace_in_literal_matrix = e_indexing = 0 ------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.octave.org How to fund new projects: http://www.octave.org/funding.html Subscription information: http://www.octave.org/archive.html -------------------------------------------------------------