Re: Complexity explosion in linear solve
- To: mathgroup at smc.vnet.net
- Subject: [mg80288] Re: Complexity explosion in linear solve
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Thu, 16 Aug 2007 07:22:18 -0400 (EDT)
- Organization: The Open University, Milton Keynes, UK
- References: <200708141107.HAA09644@smc.vnet.net><f9ueas$b9n$1@smc.vnet.net> <fa12qe$mn6$1@smc.vnet.net>
carlos at colorado.edu wrote:
>> Try Method->"OneStepRowReduction" (without quotes, if in versions < 6) and
--------------------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> see if that helps.
<snip>
>> Daniel Lichtblau
>> Wolfram Research
>
> When I tried that option under version 5.2 for Mac OS X,
> the expression returns unevaluated. I could not find documentation
> for it; what does it do?
<snip>
Have you tried without quotes? Without quotes surrounding the value for
the option, the following works fine on my system.
In[1]:=
$Version
mat = {{1, 2, 3}, {1, 3, 4}};
b = {5, 8};
x = LinearSolve[mat, b, Method -> OneStepRowReduction]
Out[1]=
5.2 for Microsoft Windows (June 20, 2005)
Out[4]=
{-1, 3, 0}
(More information can be found in Michael Trott's _The Mathematica
GuideBook for Programming_, p 826: "Method is an option for the commands
LinearSolve, Inverse, RowReduce (to be treated soon), and NullSpace. It
defines the internal algorithm to be used in the computation. Default:
Automatic. Admissible: DivisionFreeRowReduction or CofactorExpansion or
OneStepRowReduction.")
HTH
--
Jean-Marc
- References:
- Complexity explosion in linear solve
- From: carlos@colorado.edu
- Complexity explosion in linear solve