Math Help (Matrix Stuff)

Discussion in 'Technical Discussion' started by saxman, Jun 4, 2011.

  1. saxman

    saxman

    Oldbie Tech Member
    Augmented matrix:

    [ 008, 004, 002, 001, 4 ]
    [ 027, 009, 003, 001, 5 ]
    [ 216, 036, 006, 001, 7 ]
    [ 512, 064, 008, 001, 4 ]



    Linear system:

    A(008) + B(004) + C(002) + D = 4
    A(027) + B(009) + C(003) + D = 5
    A(216) + B(036) + C(006) + D = 7
    A(512) + B(064) + C(008) + D = 4



    I'm trying to solve for A, B, C, and D. It's been a long, long time since I've done this kind of thing. Can anyone help?
     
  2. Synergy

    Synergy

    Member
    90
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    UK
    Sounds like you're after <a href="http://en.wikipedia.org/wiki/Gaussian_elimination" target="_blank">Gaussian elimination</a>?
     
  3. Shadow Hog

    Shadow Hog

    "I'm a superdog!" Member
    Code (Text):
    1. [&nbsp;&nbsp;0,&nbsp;&nbsp; 0,&nbsp;&nbsp; 0,&nbsp;&nbsp;60, 216]
    2. [&nbsp;&nbsp;0,&nbsp;&nbsp; 0, 120,&nbsp;&nbsp; 0, -82]
    3. [&nbsp;&nbsp;0, 120,&nbsp;&nbsp; 0,&nbsp;&nbsp; 0,&nbsp;&nbsp;67]
    4. [120,&nbsp;&nbsp; 0,&nbsp;&nbsp; 0,&nbsp;&nbsp; 0,&nbsp;&nbsp;-7]
    ...is what I got from reduced-row-echelon form, outside of the fact that the rows are kind of in reverse order and are weighted by multiples of 60.

    Code (Text):
    1. [&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0, -7/120]
    2. [&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 1,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0, 67/120]
    3. [&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 1,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0, -41/60]
    4. [&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 0,&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 1,&nbsp;&nbsp; 18/5]
    Eliminates those issues.