RE: Bug report for MathixExp applied to a matrix of more-than-machine-precision numbers.
- To: mathgroup at smc.vnet.net
- Subject: [mg46765] RE: [mg46749] Bug report for MathixExp applied to a matrix of more-than-machine-precision numbers.
- From: "David Park" <djmp at earthlink.net>
- Date: Sun, 7 Mar 2004 01:33:43 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Sasha,
It works in 5.0.0.
MatrixExp[mat]
{{0.629715926773139433128201219496689223889890000573,
0.043272133628995532550007419267088674906992865756, \
-0.775619348662370882970279342923966405559596934692}, \
{-0.758122129833913698997991421827919657171707362198,
0.252008191520039596335048190450292895463503812363, \
-0.601450503086404894412320958240615636790215514137}, \
{0.169436382823573626402281120713124219469209126192,
0.966757153507535933149169968280951493199873521568,
0.191499133986736366584649123028828807021013925819}}
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: Oleksandr Pavlyk [mailto:pavlyk at phys.psu.edu]
To: mathgroup at smc.vnet.net
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`49.296
724682967415,
-0.7254275036630691476762861174949573251764090399344597452533905218986`49.29
6724682967415},
{-0.6151525466966055419759862386321433310005256421644620580451761964922`49.2
96724682967415,
0,
-1.2037607176452254987349374498805075260847239397930119102841747928461`49.29
6724682967415},
{0.7254275036630691476762861174949573251764090399344597452533905218986`49.29
6724682967415,
1.2037607176452254987349374498805075260847239397930119102841747928461`49.296
724682967415,
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