Re: help create a unique solution system
- To: mathgroup at smc.vnet.net
- Subject: [mg27673] Re: help create a unique solution system
- From: "cdes" <cdes43 at videotron.ca>
- Date: Sat, 10 Mar 2001 00:50:10 -0500 (EST)
- References: <9850ep$5jr@smc.vnet.net> <98a1j4$cpc@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Thanks mr Giroux but this kinda solution is too complicated..... I'd like to
do the same but without any programming
MC
"Andre Giroux" <giroux at dms.umontreal.ca> a écrit dans le message news:
98a1j4$cpc at smc.vnet.net...
> Hi Mc.
> Here is a solution.
> It is based on a theorem of Hadamard according to which a matrice a[[i,j]]
> is non-singular provided that
> |a[[i,i]] | > sum |a[[i,j]]| for each row i.
>
> \!\(\(n = 5;\)\n
> \(offDiag =
> Table[If[i == j,
> 0, \(\((\(-1\))\)\^Random[Integer]\) Random[Integer, {1, 20}]],
> {i,
> n}, {j, n}];\)\n
> \(onDiag =
> Table[\(\((\(-1\))\)\^Random[Integer]\)
> Random[Integer, {\[Sum]\+\(j = 1\)\%n Abs[
> offDiag[\([\)\(i, j\)\(]\)]] +
> 1, \[Sum]\+\(j = 1\)\%n Abs[offDiag[\([\)\(i, j\)\(]\)]] +
> 20}], {i, n}];\)\n
> matrice =
> Table[If[i == j, onDiag[\([\)\(i\)\(]\)] + offDiag[\([\)\(i,
j\)\(]\)],
> offDiag[\([\)\(i, j\)\(]\)]], {i, n}, {j, n}]\)
>
> The setting up of the equations once the coefficient matrice is known is
> left as an exercise ;-) .
>
> "cdes" <cdes43 at videotron.ca> a écrit dans le message news:
> 9850ep$5jr at smc.vnet.net...
> > Could someone help me create a unique solution system of 5 random linear
> > equations with 5 unknown x1, x2, x3, x4, x5, with integer coefficients
> > (different from zero) and second members integers (all different from
> zero).
> > Thanks in advance,
> > Mc
> > kaoum at videotron.ca