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...