Bug report for MathixExp applied to a matrix of more-than-machine-precision numbers.
- To: mathgroup at smc.vnet.net
- Subject: [mg46749] Bug report for MathixExp applied to a matrix of more-than-machine-precision numbers.
- From: Oleksandr Pavlyk <pavlyk at phys.psu.edu>
- Date: Fri, 5 Mar 2004 01:47:00 -0500 (EST)
- Organization: Penn State University; Department of Physics
- Reply-to: pavlyk at phys.psu.edu
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
I am not sure on how to report a bug in Mathematica, so
I would write to the forum, knowing that the list is
modetated :)
In[1]:=
$Version
Out[1]=
"5.0 for Microsoft Windows (June 11, 2003)"
In[2]:=
mat = {{0,
0.6151525466966055419759862386321433310005256421644620580451761964922`49.296724682967415,
-0.7254275036630691476762861174949573251764090399344597452533905218986`49.296724682967415},
{-0.6151525466966055419759862386321433310005256421644620580451761964922`49.296724682967415,
0,
-1.2037607176452254987349374498805075260847239397930119102841747928461`49.296724682967415},
{0.7254275036630691476762861174949573251764090399344597452533905218986`49.296724682967415,
1.2037607176452254987349374498805075260847239397930119102841747928461`49.296724682967415,
0}};
In[3]:=
MatrixExp[mat]
generates Divide::indet, Divide::infy, \[Infinity]::"indet" errors
before Windows reports a crash of MathKernel, and shuts it down
prompting to report the incident to Microsoft.
Trying to reduce the accuracy helps to get the final result
In[4]:=
MatrixExp[N[mat,5]]
Out[4]=
{{0.6297160719436076796`3.7756975065769325,
0.0432721390753584633`2.6576010298827444,
-0.7756190709530262614`3.833969641768763},
{-0.7581218549510174401`3.8696850920659425,
0.25200848487286692`3.4668879073986285,
-0.6014503110645328147`3.693042910203886},
{0.1694363428295855821`3.1961977983341225,
0.9667568181352670783`3.8868215583540806,
0.1914994511208260971`3.1806736750156337}}
Best regards,
Sasha