FIND on a 0x0 returns a 0x1
Carsten Clark
tantumquantum+gnuoctave at gmail.com
Wed Mar 25 00:49:28 CDT 2009
--------
Bug report for Octave 3.0.3 configured for i686-pc-cygwin
Description:
-----------
* When FIND is called on a 0x0 matrix, it returns a 0x1
empty matrix. This is inconvenient because a FOR loop
will be entered when given a 0x1 empty matrix to
iterate over.
For reference, FIND in MATLAB R2007b returns a 0x0
empty matrix in the same situation, and a FOR loop
over the result is not entered.
My vote would be that it would make more sense for FIND
to return a 0x0 when given a 0x0. However, on some other
inputs, both Octave's and MATLAB's FIND functions will
return a 0x1, which a FOR loop will enter. So perhaps
the proper behavior is up for debate, and I should change
my code ;-)
Repeat-By:
---------
Here are trivial and a practical examples in Octave and MATLAB:
(In Octave 3.0.3)
$ octave -qf
octave:1> find ( [] )
ans = [](0x1)
octave:2> for c = find ( [] ), c, end
c = [](0x1)
$ octave -qf
octave:1> tracks = repmat ( struct ('active', 0), 1, 0 );
octave:2> w = [tracks.active]
w = [](0x0)
octave:3> for inx = find(w), inx, end
inx = [](0x1)
(In MATLAB R2007b)
>> find ( [] )
ans =
[]
>> size(ans)
ans =
0 0
>> for c = find ( [] ), c, end
>>
>> tracks = repmat ( struct ('active', 0), 1, 0 );
>> w = [tracks.active]
w =
[]
>> size(w)
ans =
0 0
>> for inx = find(w), inx, end
>>
Fix:
---
* I can work around this using my own FIND dispatch.
I don't have a fix for the builtin FIND.
Configuration (please do not edit this section):
-----------------------------------------------
uname output: CYGWIN_NT-5.1 sony 1.5.25(0.156/4/2) 2008-06-12
19:34 i686 Cygwin
configure opts:
'--srcdir=/cygdrive/c/cygwin/pub/cygports/octave/new/octave-3.0.3-1/src/octave-3.0.3'
'--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin'
'--sbindir=/usr/sbin' '--libexecdir=/usr/sbin' '--datadir=/usr/share'
'--localstatedir=/var' '--sysconfdir=/etc' '--datarootdir=/usr/share'
'--docdir=/usr/share/doc/octave-3.0.3' '--libexecdir=/usr/lib'
'--enable-shared' 'CFLAGS=-Dtimezone=_timezone' 'CC=gcc-4'
'F77=gfortran-4' 'CXX=g++-4' 'CPP=cpp-4' 'LDFLAGS=' 'LIBS='
'CPPFLAGS=' 'CXXFLAGS=-O2 -pipe '
Fortran compiler: gfortran-4
FFLAGS: -O -mieee-fp
F2C: @F2C@
F2CFLAGS: @F2CFLAGS@
FLIBS: -L/bin/../lib/gcc/i686-pc-cygwin/4.3.2
-L/bin/../lib/gcc -L/usr/lib/gcc/i686-pc-cygwin/4.3.2
-L/bin/../lib/gcc/i686-pc-cygwin/4.3.2/../../.. -lhdf5 -lz -lm
-lgfortranbegin -lgfortran -lcygwin -luser32 -lkernel32 -ladvapi32
-lshell32
CPPFLAGS:
INCFLAGS: -I.
-I/cygdrive/c/cygwin/pub/cygports/octave/new/octave-3.0.3-1/src/octave-3.0.3
-I. -I./liboctave -I./src -I./libcruft/misc
-I/cygdrive/c/cygwin/pub/cygports/octave/new/octave-3.0.3-1/src/octave-3.0.3
-I/cygdrive/c/cygwin/pub/cygports/octave/new/octave-3.0.3-1/src/octave-3.0.3/liboctave
-I/cygdrive/c/cygwin/pub/cygports/octave/new/octave-3.0.3-1/src/octave-3.0.3/src
-I/cygdrive/c/cygwin/pub/cygports/octave/new/octave-3.0.3-1/src/octave-3.0.3/libcruft/misc
C compiler: gcc-4, version 4.3.2 20080827 (alpha-testing) 1 (GCC)
CFLAGS: -Dtimezone=_timezone
CPICFLAG:
C++ compiler: g++-4, version 4.3.2
CXXFLAGS: -O2 -pipe
CXXPICFLAG:
LD_CXX: g++-4
LDFLAGS:
LIBFLAGS: -L.
RLD_FLAG:
BLAS_LIBS: -llapack -lblas
FFTW_LIBS: -lfftw3
LIBS: -lreadline -lncurses -ldl -lwsock32 -lhdf5 -lz -lm -lwsock32
LEXLIB:
LIBGLOB:
SED: /bin/sed
DEFS:
-DPACKAGE_NAME="" -DPACKAGE_TARNAME="" -DPACKAGE_VERSION=""
-DPACKAGE_STRING="" -DPACKAGE_BUGREPORT="" -DOCTAVE_SOURCE=1
-DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1
-DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1
-DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1
-DHAVE_UNISTD_H=1 -D__EXTENSIONS__=1 -D_ALL_SOURCE=1 -D_GNU_SOURCE=1
-D_POSIX_PTHREAD_SEMANTICS=1 -D_TANDEM_SOURCE=1 -D__EXTENSIONS__=1
-D_ALL_SOURCE=1 -D_GNU_SOURCE=1 -D_POSIX_PTHREAD_SEMANTICS=1
-D_TANDEM_SOURCE=1 -D__EXTENSIONS__=1 -D_ALL_SOURCE=1 -D_GNU_SOURCE=1
-D_POSIX_PTHREAD_SEMANTICS=1 -D_TANDEM_SOURCE=1 -DSEPCHAR=':'
-DSEPCHAR_STR=":" -D__NO_MATH_INLINES=1 -DCXX_NEW_FRIEND_TEMPLATE_DECL=1
-DCXX_ISO_COMPLIANT_LIBRARY=1 -DCXX_ABI=gnu_v3 -DHAVE_LIBM=1
-DHAVE_QHULL=1 -DHAVE_PCRE=1 -DHAVE_REGEXEC=1 -DHAVE_REGEX=1
-DHAVE_ZLIB_H=1 -DHAVE_ZLIB=1 -DHAVE_HDF5_H=1 -DHAVE_HDF5=1
-DHAVE_H5GGET_NUM_OBJS=1 -DHAVE_FFTW3=1 -DHAVE_GLPK_H=1 -DHAVE_GLPK=1
-DHAVE_CURL_CURL_H=1 -DHAVE_CURL=1 -DHAVE_IEEE754_DATA_FORMAT=1
-DF77_FUNC(name,NAME)=name ## _ -DF77_FUNC_(name,NAME)=name ## _
-DHAVE_BLAS=1 -DHAVE_SUITESPARSE_UMFPACK_H=1 -DHAVE_UMFPACK=1
-DUMFPACK_SEPARATE_SPLIT=1 -DHAVE_SUITESPARSE_COLAMD_H=1
-DHAVE_COLAMD=1 -DHAVE_SUITESPARSE_CCOLAMD_H=1 -DHAVE_CCOLAMD=1
-DHAVE_SUITESPARSE_CHOLMOD_H=1 -DHAVE_CHOLMOD=1 -DHAVE_SUITESPARSE_CS_H=1
-DHAVE_CXSPARSE=1 -DHAVE_GETHOSTNAME=1 -DHAVE_GETPWNAM=1
-DHAVE_LIBWSOCK32=1 -DHAVE_DEV_T=1 -DHAVE_INO_T=1 -DHAVE_NLINK_T=1
-DHAVE_NLINK_T=1 -DHAVE_LONG_LONG_INT=1 -DHAVE_UNSIGNED_LONG_LONG_INT=1
-DHAVE_SIGSET_T=1 -DHAVE_SIG_ATOMIC_T=1 -DSIZEOF_SHORT=2
-DSIZEOF_INT=4 -DSIZEOF_LONG=4 -DSIZEOF_LONG_LONG=8 -DHAVE_ALLOCA_H=1
-DHAVE_ALLOCA=1 -DNPOS=std::string::npos -DHAVE_PLACEMENT_DELETE=1
-DHAVE_DYNAMIC_AUTO_ARRAYS=1 -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_GRP_H=1 -DHAVE_IEEEFP_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_LIMITS_H=1
-DHAVE_LOCALE_H=1 -DHAVE_MEMORY_H=1 -DHAVE_NCURSES_H=1 -DHAVE_POLL_H=1
-DHAVE_PWD_H=1 -DHAVE_STDINT_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_SYS_UTIME_H=1 -DHAVE_TERMCAP_H=1
-DHAVE_UNISTD_H=1 -DHAVE_UTIME_H=1 -DHAVE_SSTREAM=1 -DHAVE_TERMIO_H=1
-DHAVE_GLOB_H=1 -DHAVE_FNMATCH_H=1 -DHAVE_FNMATCH=1 -DHAVE_GLOB=1
-DHAVE_ATEXIT=1 -DHAVE_BASENAME=1 -DHAVE_BCOPY=1 -DHAVE_BZERO=1
-DHAVE_CHMOD=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_GETPGRP=1 -DHAVE_GETPID=1
-DHAVE_GETPPID=1 -DHAVE_GETPWENT=1 -DHAVE_GETPWUID=1 -DHAVE_GETTIMEOFDAY=1
-DHAVE_GETUID=1 -DHAVE_GETWD=1 -DHAVE_KILL=1 -DHAVE_LGAMMA=1 -DHAVE_LINK=1
-DHAVE_LOCALTIME_R=1 -DHAVE_LSTAT=1 -DHAVE_MEMMOVE=1 -DHAVE_MKDIR=1
-DHAVE_MKFIFO=1 -DHAVE_MKSTEMP=1 -DHAVE_ON_EXIT=1 -DHAVE_PIPE=1
-DHAVE_POLL=1 -DHAVE_PUTENV=1 -DHAVE_RAISE=1 -DHAVE_READLINK=1
-DHAVE_REALPATH=1 -DHAVE_RENAME=1 -DHAVE_RINDEX=1 -DHAVE_RMDIR=1
-DHAVE_ROUND=1 -DHAVE_SELECT=1 -DHAVE_SETGRENT=1 -DHAVE_SETLOCALE=1
-DHAVE_SETPWENT=1 -DHAVE_SETVBUF=1 -DHAVE_SIGACTION=1 -DHAVE_SIGPENDING=1
-DHAVE_SIGPROCMASK=1 -DHAVE_SIGSUSPEND=1 -DHAVE_SNPRINTF=1
-DHAVE_STAT=1 -DHAVE_STRCASECMP=1 -DHAVE_STRDUP=1 -DHAVE_STRERROR=1
-DHAVE_STRNCASECMP=1 -DHAVE_STRPTIME=1 -DHAVE_STRSIGNAL=1 -DHAVE_SYMLINK=1
-DHAVE_TEMPNAM=1 -DHAVE_TGAMMA=1 -DHAVE_UMASK=1 -DHAVE_UNAME=1
-DHAVE_UNLINK=1 -DHAVE_USLEEP=1 -DHAVE_UTIME=1 -DHAVE_VFPRINTF=1
-DHAVE_VSPRINTF=1 -DHAVE_VSNPRINTF=1 -DHAVE_WAITPID=1 -DHAVE__CHMOD=1
-DHAVE__SNPRINTF=1 -DHAVE_STRFTIME=1 -DOCTAVE_HAVE_BROKEN_STRPTIME=1
-DHAVE_LIBDL=1 -DHAVE_DLOPEN=1 -DHAVE_DLSYM=1 -DHAVE_DLERROR=1
-DHAVE_DLCLOSE=1 -DHAVE_DLOPEN_API=1 -DENABLE_DYNAMIC_LINKING=1
-DHAVE_TIMEVAL=1 -DHAVE_FINITE=1 -DHAVE_ISNAN=1 -DHAVE_ISINF=1
-DHAVE_COPYSIGN=1 -DHAVE__FINITE=1 -DHAVE__ISNAN=1 -DHAVE__COPYSIGN=1
-DHAVE_DECL_SIGNBIT=1 -DHAVE_ACOSH=1 -DHAVE_ASINH=1 -DHAVE_ATANH=1
-DHAVE_ERF=1 -DHAVE_ERFC=1 -DHAVE_EXP2=1 -DHAVE_STRUCT_STAT_ST_BLKSIZE=1
-DHAVE_STRUCT_STAT_ST_BLOCKS=1 -DHAVE_STRUCT_STAT_ST_RDEV=1
-DHAVE_DECL_TZNAME=1 -DHAVE_TZNAME=1 -DUSE_READLINE=1
-DEXCEPTION_IN_MATH=1 -DRETSIGTYPE=void -DHAVE_DECL_SYS_SIGLIST=0
-DHAVE_POSIX_SIGNALS=1 -DRETSIGTYPE_IS_VOID=1 -DHAVE_GETRUSAGE=1
-DHAVE_TIMES=1 -DRUSAGE_TIMES_ONLY=1 -DYYTEXT_POINTER=1
-DGNUPLOT_BINARY="gnuplot"
User-preferences (please do not edit this section):
--------------------------------------------------
EDITOR = emacs
EXEC_PATH = /usr/lib/octave/3.0.3/site/exec/i686-pc-cygwin:/usr/lib/octave/api-v32/site/exec/i686-pc-cygwin:/usr/lib/octave/site/exec/i686-pc-cygwin:/usr/lib/octave/3.0.3/exec/i686-pc-cygwin:/usr/bin:/cygdrive/c/users/carsten/bin:/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin:/cygdrive/c/WINDOWS/system32:/cygdrive/c/WINDOWS:/cygdrive/c/WINDOWS/system32/wbem:/cygdrive/c/program
files/perforce:/cygdrive/c/Program
Files/MATLAB/R2007b/bin:/cygdrive/c/Program
Files/MATLAB/R2007b/bin/win32:/cygdrive/c/Program
Files/Intel/WiFi/bin/:/cygdrive/c/Program
Files/QuickTime/QTSystem/:/usr/lib/lapack
IMAGE_PATH = .:/usr/share/octave/3.0.3/imagelib
PAGER = less
PS1 = \s:\#>
PS2 = >
PS4 = +
beep_on_error = 0
completion_append_char =
crash_dumps_octave_core = 1
echo_executing_commands = 0
fixed_point_format = 0
gnuplot_binary = gnuplot
gnuplot_command_end =
gnuplot_command_plot = pl
gnuplot_command_replot = rep
gnuplot_command_splot = sp
gnuplot_command_title = t
gnuplot_command_using = u
gnuplot_command_with = w
history_file = /cygdrive/c/users/carsten/.octave_hist
history_size = 1024
ignore_function_time_stamp = system
info_file = /usr/share/info/octave.info
info_program = info
makeinfo_program = makeinfo
max_recursion_depth = 256
output_max_field_width = 5
output_precision = 5
page_output_immediately = 0
page_screen_output = 1
print_answer_id_name = 1
print_empty_dimensions = 1
save_precision = 16
saving_history = 1
sighup_dumps_octave_core = 1
sigterm_dumps_octave_core = 1
silent_functions = 0
split_long_rows = 1
string_fill_char =
struct_levels_to_print = 2
suppress_verbose_help_message = 0
More information about the Bug-octave
mailing list