Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2004
*January
*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 2004

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

Search the Archive

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



  • Prev by Date: Re: DSolve change in v5 -- undocumented error message
  • Next by Date: Re: Bug report for MathixExp applied to a matrix of more-than-machine-precision numbers.
  • Previous by thread: Re: Bug report for MathixExp applied to a matrix of more-than-machine-precision numbers.
  • Next by thread: Re: Bug report for MathixExp applied to a matrix of more-than-machine-precision numbers.