Re: Eigenvalue bug in Mathematica 7.0.0

*To*: mathgroup at smc.vnet.net*Subject*: [mg101233] Re: Eigenvalue bug in Mathematica 7.0.0*From*: ADL <alberto.dilullo at tiscali.it>*Date*: Sat, 27 Jun 2009 06:05:08 -0400 (EDT)*References*: <h22974$hqb$1@smc.vnet.net>

Mark, with version 7.0 for Microsoft Windows (32-bit) (February 18, 2009), I get this: {eivals, eivecs} = Eigensystem[H]; In[]:= And @@ Table[ Chop[Norm[H.eivecs[[i]] - eivals[[i]] eivecs[[i]]]] == 0, {i, Length[eivals]} ] Out[]= True So I think the result is correct. ADL On Jun 26, 12:51 pm, Mark Saffman <msaff... at wisc.edu> wrote: > I find that Mathematica V7.0.0 finds incorrect eigenvalues and eigenvecto= rs of the 100 x 100 real symmetric matrix listed below. You can easily chec= k the first eigenvector produced is not a true eigenvector. > > I get incorrect results running under > Windows Vista 64 bit, Windows Server 2003 32 bit, Windows Server 2003 64 = bit. I get correct results running under Windows Vista 32 bit. All of the a= bove systems produce correct results if I evaluate with Mathematica V6.0.1.= 0. > > I consider this a very serious error. Here is the > 100 x 100 matrix: > ....