Here it hangs with 100% CPU of one core (of a dual core CPU) : octave:1> a = [1;2;3]; octave:2> b = a'; octave:3> c = a * b; octave:4> c / (inv (c)); warning: inverse: matrix singular to machine precision, rcond = 0 warning: matrix singular to machine precision, rcond = nan Reproducible: Always tfoerste@n22 ~ $ emerge --info sci-mathematics/octave Portage 2.1.11.5 (default/linux/x86/10.0/desktop/kde, gcc-4.5.3, glibc-2.14.1-r3, 3.4.4 i686) ================================================================= System Settings ================================================================= System uname: Linux-3.4.4-i686-Intel-R-_Core-TM-2_Duo_CPU_P8600_@_2.40GHz-with-gentoo-2.1 Timestamp of tree: Fri, 06 Jul 2012 17:15:01 +0000 app-shells/bash: 4.2_p20 dev-java/java-config: 2.1.11-r3 dev-lang/python: 2.7.3-r2, 3.2.3 dev-util/cmake: 2.8.7-r5 dev-util/pkgconfig: 0.26 sys-apps/baselayout: 2.1-r1 sys-apps/openrc: 0.9.8.4 sys-apps/sandbox: 2.5 sys-devel/autoconf: 2.13, 2.68 sys-devel/automake: 1.9.6-r3, 1.11.1 sys-devel/binutils: 2.21.1-r1 sys-devel/gcc: 4.5.3-r2 sys-devel/gcc-config: 1.6 sys-devel/libtool: 2.4-r1 sys-devel/make: 3.82-r1 sys-kernel/linux-headers: 3.1 (virtual/os-headers) sys-libs/glibc: 2.14.1-r3 Repositories: gentoo toralf ACCEPT_KEYWORDS="x86" ACCEPT_LICENSE="*" CBUILD="i686-pc-linux-gnu" CFLAGS="-O2 -march=native -pipe" CHOST="i686-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/config /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php5.3/ext-active/ /etc/php/cgi-php5.3/ext-active/ /etc/php/cli-php5.3/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-O2 -march=native -pipe" DISTDIR="/usr/portage/distfiles" EMERGE_DEFAULT_OPTS="--autounmask=n --keep-going=y --nospinner --tree --deep --quiet-build" FCFLAGS="-O2 -march=i686 -pipe" FEATURES="assume-digests binpkg-logs compress-build-logs config-protect-if-modified distlocks ebuild-locks fixlafiles news parallel-fetch parse-eapi-ebuild-head protect-owned sandbox sfperms strict test test-fail-continue unknown-features-warn unmerge-logs unmerge-orphans userfetch" FFLAGS="-O2 -march=i686 -pipe" GENTOO_MIRRORS="http://mirror.leaseweb.com/gentoo/ http://gentoo.mirror.dkm.cz/pub/gentoo/ http://ftp.snt.utwente.nl/pub/os/linux/gentoo http://gentoo.mneisen.org/ http://www.gtlib.gatech.edu/pub/gentoo" LANG="en_US.utf8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" LINGUAS="en en_GB" MAKEOPTS="-j3" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" SYNC="rsync://linux.rz.ruhr-uni-bochum.de/gentoo-portage" USE="X a52 aac acl acpi alsa apache2 berkdb bittorrent branding bzip2 cairo cdda cdr classic cli consolekit corefonts cracklib crypt css cups cxx dbus declarative dri dts dvb dvd dvdr emboss encode exif fam fastbuild ffmpeg firefox flac fontconfig fortran g3dvl gdbm gif git gmp gphoto2 gpm gtk hyphenation iconv ipv6 java jpeg kde kipi kqemu kvm lcms ldap libnotify lirc logrotate mad mbox mmx mng modules mp3 mp4 mpeg mudflap mysql mysqli ncurses nls nptl nsplugin ntfs ogg opengl openmp pam pango pcre pdf phonon plasma png policykit ppds pppd qt3support qt4 rdesktop readline sdl session sna spell sse sse2 sse3 ssl ssse3 startup-notification svg tcpd thinkpad threads tiff tk transparent-proxy truetype udev udisks unicode upower usb vim-syntax vnc vorbis wxwidgets x264 x86 xa xcb xcomposite xinerama xml xorg xpm xscreensaver xv xvid xvmc zlib" ALSA_CARDS="hda-intel" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic auth_digest authn_anon authn_dbd authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi dav dav_fs dav_lock dbd deflate dir disk_cache env expires ext_filter file_cache filter headers ident imagemap include info log_config logio mem_cache mime mime_magic negotiation proxy proxy_ajp proxy_balancer proxy_connect proxy_http rewrite setenvif so speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ubx" INPUT_DEVICES="evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LINGUAS="en en_GB" LIRC_DEVICES="devinput inputlirc" PHP_TARGETS="php5-3" PYTHON_TARGETS="python3_2 python2_7" QEMU_SOFTMMU_TARGETS="i386 x86_64" QEMU_USER_TARGETS="i386 x86_64" RUBY_TARGETS="ruby18 ruby19" USERLAND="GNU" VIDEO_CARDS="intel" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CPPFLAGS, CTARGET, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON ================================================================= Package Settings ================================================================= sci-mathematics/octave-3.6.2-r1 was built with the following: USE="X (consolekit) glpk imagemagick opengl (policykit) qhull qrupdate readline sparse test zlib -curl -doc -fftw -gnuplot -hdf5 -static-libs"
hi, could you be clearer on what is the problem and how we could reproduce it? this matrix looks singular to me, so it's normal you get something a message like that on an non-invertible matrix. does it hang when it produces the message? thanks,
(In reply to comment #1) > does it hang when it produces the > message? yes, I have to press Ctrl-C to continue.
could you give the output of: pkg-config --libs lapack
tfoerste@n22 ~ $ pkg-config --libs lapack -llapack -lblas
I compiled sci-libs/lapack-reference with "splitdebug" but gdb tells me : Reading symbols from /usr/lib/liblapack.so.0...(no debugging symbols found)...done. Loaded symbols for /usr/lib/liblapack.so.0 Despite theat the debug info is made : tfoerste@n22 ~ $ equery f sci-libs/lapack-reference * Searching for lapack-reference in sci-libs ... * Contents of sci-libs/lapack-reference-3.1.1-r1: /etc /etc/env.d /etc/env.d/lapack /etc/env.d/lapack/lib /etc/env.d/lapack/lib/reference /usr /usr/lib /usr/lib/debug /usr/lib/debug/usr /usr/lib/debug/usr/lib /usr/lib/debug/usr/lib/lapack /usr/lib/debug/usr/lib/lapack/reference /usr/lib/debug/usr/lib/lapack/reference/liblapack.so.0.0.0.debug /usr/lib/lapack /usr/lib/lapack/reference /usr/lib/lapack/reference/lapack.pc /usr/lib/lapack/reference/liblapack.a /usr/lib/lapack/reference/liblapack.la /usr/lib/lapack/reference/liblapack.so -> liblapack.so.0.0.0 /usr/lib/lapack/reference/liblapack.so.0 -> liblapack.so.0.0.0 /usr/lib/lapack/reference/liblapack.so.0.0.0 /usr/share /usr/share/doc /usr/share/doc/lapack-reference-3.1.1-r1 /usr/share/doc/lapack-reference-3.1.1-r1/README.bz2 Nevertheless U started octave and derived a back trace from gdb by attaching it to the pid of octave. After I pressed Ctrl-C I got : Program received signal SIGINT, Interrupt. 0xb5410c5f in dlascl_ () from /usr/lib/liblapack.so.0 (gdb) bt #0 0xb5410c5f in dlascl_ () from /usr/lib/liblapack.so.0 #1 0xb55f19cd in dgelsd_ () from /usr/lib/liblapack.so.0 #2 0xb6210dfd in Matrix::lssolve (this=0xbfd78f8c, b=..., info=@0xbfd790dc, rank=@0xbfd78efc, rcon=@0xbfd790c8) at dMatrix.cc:2361 #3 0xb62160ce in Matrix::solve (this=0xbfd78f8c, mattype=..., b=..., info=@0xbfd790dc, rcon=@0xbfd790c8, sing_handler= 0xb6fa0950 <solve_singularity_warning(double)>, singular_fallback=true, transt=blas_no_trans) at dMatrix.cc:1971 #4 0xb6216169 in Matrix::solve (this=0xbfd791a0, mattype=..., b=..., info=@0xbfd790dc, rcon=@0xbfd790c8, sing_handler=0xb6fa0950 <solve_singularity_warning(double)>, singular_fallback=true, transt=blas_trans) at dMatrix.cc:1958 #5 0xb6fa4162 in xdiv (a=..., b=..., typ=...) at xdiv.cc:140 #6 0xb735a8de in oct_binop_div (a1=..., a2=...) at OPERATORS/op-m-m.cc:73 #7 0xb70c41fe in do_binary_op (op=octave_value::op_div, v1=..., v2=...) at ov.cc:1903 #8 0xb7153ad1 in tree_binary_expression::rvalue1 (this=0x95984e8) at pt-binop.cc:132 #9 0xb71621b8 in tree_evaluator::visit_statement (this=0xb772356c, stmt=...) at pt-eval.cc:736 #10 0xb7195beb in tree_statement::accept (this=0x9437ec8, tw=...) at pt-stmt.cc:151 #11 0xb7162cae in tree_evaluator::visit_statement_list (this=0xb772356c, lst=...) at pt-eval.cc:772 #12 0xb7195cbb in tree_statement_list::accept (this=0x940c898, tw=...) at pt-stmt.cc:215 #13 0xb6f77e74 in main_loop () at toplev.cc:595 #14 0xb6f0414b in octave_main (argc=1, argv=0xbfd79854, embedded=0) at octave.cc:943 #15 0x080485b3 in main (argc=1, argv=0xbfd79854) at main.c:35
Solved by sci-libs/lapack-reference-3.2.1-r1, where I get : octave:1> a = [1;2;3]; b = a'; c = a * b; c / (inv (c)); warning: inverse: matrix singular to machine precision, rcond = 0 warning: matrix singular to machine precision, rcond = nan ** On entry to DLASCL parameter number 4 had an illegal value error: exception encountered in Fortran subroutine dgelsd_ octave:1>
4 years old ...
