Re: What function to use to find matrix condition number?

*To*: mathgroup at smc.vnet.net*Subject*: [mg114415] Re: What function to use to find matrix condition number?*From*: Oliver Ruebenkoenig <ruebenko at wolfram.com>*Date*: Fri, 3 Dec 2010 06:30:44 -0500 (EST)*References*: <201012031022.FAA20405@smc.vnet.net>

Hi Nasser, On Fri, 3 Dec 2010, Nasser M. Abbasi wrote: > This is version 8: > > I'd like to use LinearAlgebra`MatrixConditionNumber to find > condition number of some matrix. > > btw, This command lists the functions in linear algebra. > Names["LinearAlgebra`*"] > > But Mathematica says this package is now obsolete, and > functionality is now in the kernel. > > <<LinearAlgebra` > General::obspkg: {At Line = 3, the input was:, > <<LinearAlgebra`,LinearAlgebra`} is now obsolete. The > legacy version being loaded may conflict with current > Mathematica functionality. See the Compatibility Guide for > updating information. >> > > But When I follow the above, I get to page, where at the bottom > it shows 3 functions, one of them is MatrixConditionNumber, > but it does not show what replaced it in the kernel, instead > it points to a link to MathSource article: > > "These functions were available in previous versions of Mathematica > and are now available on the web at > library.wolfram.com/infocenter/MathSource/6770" > > ? > > So, is there no build-in function to compute condition number now > in Mathematica? > I made the suggestion that MatrixConditionNumber become a true kernel function. I still use the LinearAlgebra`MatrixConditionNumber to find the condition number. > I know I can find the max eigenvalue, divide it by the min > eigenvalue (absolute values), and this gives me the condition > number. But should not such a function be part of the system? > Yes, I agree. Oliver > Or may be I overlooked it? I did search for it, can't find it > in the documenation center. > > btw, I did also try the natural language interface also, and I asked > W/ALpha by typing > > = matrix condition number > > but it replied back with a chemical formula C16 H13 C1 N2 O, named diazepam, which is not what I wanted. > > thanks, > --Nasser > >

**References**:**What function to use to find matrix condition number?***From:*"Nasser M. Abbasi" <nma@12000.org>