Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calculators Ti89 error

  1. Apr 25, 2004 #1
    I met such such command for the 89 or the TI series...


    ref=gaussian elemination...

    rref=refined version of Gaussian...

    I wonder who this thing works... Because for the basic circuit problems with like 7 currents... This rref is VERY nifty. If you set up the equations wrong, the answer do not report right and you have to go back and check every darn coefficient again... Then redo the whole thing until it does come out right...


    Like, I know that nint uses Newtonian approximation, just want to know how this rref works...
     
  2. jcsd
  3. Apr 25, 2004 #2

    enigma

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    It just follows a row reduction algorithm, AFAIK. I programmed a simple one a few years back. The TI-89 most likely has several optimization checks (zeros along the diagonal, etc.) which mine didn't do.
    ref is short for "reduce to echelon form"
     
  4. Apr 25, 2004 #3
    Hmm... so that reduce to echelon form is same as the process of Gaussian elemination?
     
  5. Apr 26, 2004 #4

    enigma

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Gauss-Jordan, I believe. Don't know if that's any different from what you're referring to.

    I don't know if that's exactly what they do. I know that's one way to do it.
     
  6. Jun 11, 2004 #5
    I know this thread is pretty old but let me put my two cents in.

    I have a ti-89. rref ref were my friends in linear algerbra and circuit theory.

    rref spat out the solution instantly giving a identity matrix next to the soulutions.

    The ref command stopped short, so that x and y coefficients equaled 1. It reduced the amount of operations one would need to complete Gaussian elimination.

    I'm talking about a 2x2 matrix with the solution column vector.
    It gets real sweet when you have to solve a 3x3 matrix

    If my instuctor wanted me to show my work then these commands saved my life during exams.

    mRow
    rowAdd

    Gaussian Elimination was a snap because I had all the steps on my screen. Doing by hand was messy as hell if you made a mistake.
     
  7. Jun 14, 2004 #6
    from what i just learned, gausian elimination(ref) is a matrix row operation reduce to an upper triangular.

    but the RREF or reduce row echelon form is a refine form of gausian elimination of the [A] matrix to an "identity-like" matrix to find the solution, (constant).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Ti89 error
  1. Network error (Replies: 7)

  2. MIT Error? (Replies: 3)

  3. A windows error. (Replies: 15)

  4. Oledlg.dll error (Replies: 6)

  5. CRC error (Replies: 2)

Loading...