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}

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

```

• Prev by Date: Re: Extracting terms of a multivariate polynomial order by order
• Next by Date: Re: FindRoot and Interpolating function
• Previous by thread: Re: Complexity explosion in linear solve
• Next by thread: Re: Complexity explosion in linear solve