Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1989
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1989

[Date Index] [Thread Index] [Author Index]

Search the Archive

linear algebra bugs

  • Subject: linear algebra bugs
  • From: uunet!byuvax.bitnet!SMITHW
  • Date: Fri, 22 Sep 89 11:24:48 -0500
  • Apparently-to: mathgroup-out at yoda.ncsa.uiuc.edu

  I have encountered some interesting bugs in the linear algebra package
in mathematica on the MIPS(beta version), the Mac (1.1,1.2) and NeXT (.9 and
1.0).  Try the following:
In[1]:=
     {{1,2,3},{a,b,c},{1,2,3}}
In[2]:=
     Eigensystem[Out[1]]
     Eigensystem::eifl: Algorithm failed to find eigenvectors.
Now the same thing in Macsyma:
                                   [ 1  2  3 ]
                                   [         ]
(D7)                               [ A  0  C ]
                                   [         ]
                                   [ 1  2  3 ]

(C9) Eigenvectors(d7);

(D9) [[[2 - SQRT(2) SQRT(C + A + 2), SQRT(2) SQRT(C + A + 2) + 2, 0],

                  SQRT(2) SQRT(C + A + 2) + 2
[1, 1, 1]], [1, - ---------------------------, 1],

                             2


    SQRT(2) SQRT(C + A + 2) - 2            C - 3 A    A
[1, ---------------------------, 1], [1, - -------, - -]]
                 2                           2 C      C

This is not the only example...



  • Prev by Date: Memory and Mathematica on NeXT 1.0
  • Previous by thread: Memory and Mathematica on NeXT 1.0