Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2007
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

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

Search the Archive

RE: Button Help Example

  • To: mathgroup at smc.vnet.net
  • Subject: [mg81260] RE: [mg81238] Button Help Example
  • From: "%uvt_fullname%" <>
  • Date: Tue, 18 Sep 2007 00:33:40 -0400 (EDT)
  • References: <200709170734.DAA15516@smc.vnet.net>

Dear All,

I am facing the following problem:

1) I have a system of m=12 linear equations, with n=11 variables.

2) I want to identify those linearly dependent equations and drop them from
the system to have a solution.

3) I applied the following code (somebody from MathGroup provided this last
year), which is the Gram-Schmidt method of orthogonalization:


Clear[V];

equ = {i - 0.4 p == 0, k - 0.16 z == 0, m - 0.9 p == 0, c - 0.83 r == 0, x -
0.7 p ==0, p + m - i - c - k - x == 0, y - p + i == 0, 
  s - r + c == 0, b - m + x == 0, y - r == 0, k - s - b == 0, 
  z - p - m == 0};

{h1, V} = CoefficientArrays[equ, {p, m, i, k, x, c, y, r, s, b, z}];

Do[Do[If[V[[n]] != {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, V[[m]] =
(V[[n]].V[[n]]) V[[m]] - (V[[n]].V[[m]]) V[[n]]], {n, 1, m - 1}], {m, 2,
12}]

Map[If[# != {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, "keep", "discard"] &, V]


This Code always indicates the 6th row to be discarded no matter which order
you input the equations in "equ".

Isn't there a problem with this code or maybe I am missing something.

Your help is appreciated...

Tugrul







  • Prev by Date: Re: Single-step evaluation in Mathematica
  • Next by Date: Can an arrow be drawn on a 3D plot?
  • Previous by thread: Button Help Example
  • Next by thread: Identifying Linearly Dependent Equations