[Pkg-octave-devel] Bug#570231: octave3.2: Errors in working with complex matrices on i386
Steven De Herdt
steven.deherdt at gmail.com
Wed Feb 17 13:20:55 UTC 2010
Package: octave3.2
Version: 3.2.4-1
Severity: normal
While working with complex matrices, I noticed strange things going on.
Some searching showed that there is definitely something wrong:
octave3.2:2> a=orth(randn(3));
octave3.2:3> a'*a
ans =
1.0000e+00 -1.0742e-16 2.2264e-16
-1.0742e-16 1.0000e+00 -3.1537e-17
2.2264e-16 -3.1537e-17 1.0000e+00
octave3.2:4> b=orth(randn(3)+J*randn(3));
octave3.2:5> b'*b
ans =
1.06482 + 0.00000i 0.10484 + 0.51574i 0.14882 + 0.71172i
0.10484 - 0.51574i 0.90395 + 0.00000i -0.07914 + 0.08895i
0.14882 - 0.71172i -0.07914 - 0.08895i 1.06476 + 0.00000i
The result is Hermitian, but not quite unitary.
This also happens on octave3.0, but not on amd64 (either version).
A look through Octave's own bug reports produces e.g.
http://old.nabble.com/wrong-output-for-complex-scalar-product-to26766409.html and
http://old.nabble.com/Wrong-results-for-svd-on-complex-numbers-to27079479.html ,
so this kind of problem is not unheard of.
Depending on one's needs, this may be an 'important' bug.
-- System Information:
Debian Release: squeeze/sid
APT prefers testing
APT policy: (990, 'testing')
Architecture: i386 (i686)
Kernel: Linux 2.6.32-trunk-686 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Versions of packages octave3.2 depends on:
ii libamd2.2.0 1:3.4.0-1 approximate minimum degree orderin
ii libarpack2 2.1+parpack96.dfsg-2+b1 Fortran77 subroutines to solve lar
ii libatlas3gf-base 3.6.0-24 Automatically Tuned Linear Algebra
ii libatlas3gf-sse2 3.6.0-24 Automatically Tuned Linear Algebra
ii libblas3gf [libb 1.2-2 Basic Linear Algebra Subroutines 3
ii libbz2-1.0 1.0.5-4 high-quality block-sorting file co
ii libc6 2.10.2-2 GNU C Library: Shared libraries
ii libcamd2.2.0 1:3.4.0-1 symmetric approximate minimum degr
ii libccolamd2.7.1 1:3.4.0-1 constrained column approximate lib
ii libcholmod1.7.1 1:3.4.0-1 sparse Cholesky factorization libr
ii libcolamd2.7.1 1:3.4.0-1 column approximate minimum degree
ii libcurl3-gnutls 7.19.7-1 Multi-protocol file transfer libra
ii libcxsparse2.2.3 1:3.4.0-1 concise sparse matrix library (com
ii libfftw3-3 3.2.2-1 library for computing Fast Fourier
ii libfltk1.1 1.1.10-2 Fast Light Toolkit - shared librar
ii libfreetype6 2.3.11-1 FreeType 2 font engine, shared lib
ii libftgl2 2.1.3~rc5-3 library to render text in OpenGL u
ii libgcc1 1:4.4.2-9 GCC support library
ii libgfortran3 4.4.2-9 Runtime library for GNU Fortran ap
ii libgl1-mesa-glx 7.6.1-1 A free implementation of the OpenG
ii libglpk0 4.38-1 linear programming kit with intege
ii libglu1-mesa [li 7.6.1-1 The OpenGL utility library (GLU)
ii libgomp1 4.4.2-9 GCC OpenMP (GOMP) support library
ii libgraphicsmagic 1.3.8-1 format-independent image processin
ii libgraphicsmagic 1.3.8-1 format-independent image processin
ii libhdf5-serial-1 1.8.4-5 Hierarchical Data Format 5 (HDF5)
ii libice6 2:1.0.6-1 X11 Inter-Client Exchange library
ii libjasper1 1.900.1-6.1 The JasPer JPEG-2000 runtime libra
ii libjpeg62 6b-15 The Independent JPEG Group's JPEG
ii liblapack3gf [li 3.2.1-2 library of linear algebra routines
ii liblcms1 1.18.dfsg-1.2+b1 Color management library
ii libltdl7 2.2.6b-2 A system independent dlopen wrappe
ii libncurses5 5.7+20090803-2 shared libraries for terminal hand
ii libpcre3 7.8-3 Perl 5 Compatible Regular Expressi
ii libpng12-0 1.2.42-1 PNG library - runtime
ii libqhull5 2009.1-1 calculate convex hulls and related
ii libqrupdate1 1.0.1-1 Fast updates of QR and Cholesky de
ii libreadline6 6.1-1 GNU readline and history libraries
ii libsm6 2:1.1.1-1 X11 Session Management library
ii libstdc++6 4.4.2-9 The GNU Standard C++ Library v3
ii libtiff4 3.9.2-2 Tag Image File Format (TIFF) libra
ii libumfpack5.4.0 1:3.4.0-1 sparse LU factorization library
ii libwmf0.2-7 0.2.8.4-6.1 Windows metafile conversion librar
ii libx11-6 2:1.3.3-1 X11 client-side library
ii libxext6 2:1.1.1-2 X11 miscellaneous extension librar
ii libxml2 2.7.6.dfsg-2+b1 GNOME XML library
ii octave3.2-common 3.2.4-1 architecture-independent files for
ii texinfo 4.13a.dfsg.1-5 Documentation system for on-line i
ii zlib1g 1:1.2.3.4.dfsg-3 compression library - runtime
Versions of packages octave3.2 recommends:
ii gnuplot 4.2.6-1 A command-line driven interactive
ii libatlas3gf-base 3.6.0-24 Automatically Tuned Linear Algebra
Versions of packages octave3.2 suggests:
ii octave3.2-doc 3.2.3-1 PDF documentation on the GNU Octav
pn octave3.2-emacsen <none> (no description available)
pn octave3.2-headers <none> (no description available)
ii octave3.2-htmldoc 3.2.3-1 HTML documentation on the GNU Octa
pn octave3.2-info <none> (no description available)
-- no debconf information
More information about the Pkg-octave-devel
mailing list