mbharrin@sdcc13.ucsd.edu (Matt Harrington) (02/09/91)
I borrow a friends 48 for my linear algebra class.
We have not been able to find out how to put a matrix
into reduced row echelon form. I use Matlab, where the
command is just rref(A), where A is a matrix. The 48
comes in handy for matrix multiplication, determinants,
etc, but it would make my life infinitely more pleasurable
if it could simply row reduce a matrix. I'm sure that
we're just not looking in the right places (in the manuals).
Should I be trying to solve multiple equations with multiple
unknowns instead? I haven't tried this, but I did see
something posted about it earlier. Please send any input
to me via email.
Much thanks,
--Matt
--
Matthew B. Harrington Internet: matt@ucsd.edu
University of California at San Diego Recycle or Die.
Biophysics Think! It's not illegal
yet. d0mo@dtek.chalmers.se (Mats Olsson) (02/14/91)
>Actually Matt you're not missing it in the manuals. HP did not include >this feature in the calcualtor since I believe its only use is in solving >multivariable linear equations. This is much more easily accomplished >on the HP by the following method: ... >Then press the divide key and the answers are on the stack in the form: ----- The method described above does only work for quadratic systems of equations. Consider a system of equations with n unknowns and m equations. In matrix form the system reads: Ax=b where A is the coefficient matrix, type m*n, x is a vector containing the unknowns, type m*1, and b is a vector containing the constants on the right sides of the equations, also of type m*1. If the solution of this system of equations is determined by x=b/A, the matrix A have to be inversable and therefore quadratic. <=> m=n <=> The system of equations is quadratic. To solve a un-quadratic system of linear equations, one have to reduce the matrix into echelon form. This is easily done by my program ->RED which I will post here very soon.. Be patient!! Mats Olsson Chalmers University of technology Sweden
pashdown@javelin.es.com (Pete Ashdown) (02/15/91)
d0mo@dtek.chalmers.se (Mats Olsson) writes: >To solve a un-quadratic system of linear equations, one have to >reduce the matrix into echelon form. This is easily done by my >program ->RED which I will post here very soon.. I got this off of the mail server. Its amazingly small and efficient in comparison to other row-reducing programs. It works great! --------------------------------------------------------------------------- %%HP: T(3)A(R)F(.); @ RWRD - Matrix Row Reduction ( matrix - reduced matrix ) @ Robert T. Wilson - University of Iowa \<< DUP OBJ\-> OBJ\-> DROP \-> r c \<< r r 1 \-> m n s \<< 1 r START c \->ARRY DEPTH ROLLD NEXT 1 r START DEPTH ROLL NEXT 1 r START 0 's' STO 1 c FOR z IF DUP z GET 0 \=/ THEN z 's' STO c 'z' STO END NEXT IF s 0 > THEN DUP s GET IF 1 \=/ THEN DUP s GET / END 1 r 1 - START r ROLL IF DUP s GET 0 \=/ THEN DUP2 s GET * - 1 'n' STO END SWAP NEXT END r ROLLD NEXT r 'n' STO 1 c FOR z 1 r FOR y IF DUP z GET 1 == THEN n ROLLD 'n' DECR IF 1 == THEN r 'y' STO c 'z' STO END ELSE n ROLLD END NEXT NEXT 1 r START DEPTH ROLLD NEXT 1 r START DEPTH ROLL OBJ\-> DROP NEXT r c 2 \->LIST \->ARRY \>> \>> \>> --------------------------------------------------------------------------- >Mats Olsson >Chalmers University of technology >Sweden -- "Hi, we're 'Slaughter'. We'd just like to say how much we love our troops." Pete Ashdown pashdown@javelin.sim.es.com ...uunet!javelin.sim.es.com!pashdown
TDSTRONG%MTUS5.BITNET@CUNYVM.CUNY.EDU (Tim Strong) (02/17/91)
> >>Actually Matt you're not missing it in the manuals. HP did not include >>this feature in the calcualtor since I believe its only use is in solving >>multivariable linear equations. This is much more easily accomplished >>on the HP by the following method: >... >>Then press the divide key and the answers are on the stack in the form: >----- > >The method described above does only work for quadratic systems of equations. > Good point! I haven't had linear algebra for a long time and I'd forgotten about that one. ====================================================================== ___ :__) _ _: _ _ Tim Strong <tdstrong%mtus5.bitnet@cunyvm.edu> : \ (_: (_: (_: : Michigan Tech. Houghton, Michigan ======================================================================
jcohen@lehi3b15.csee.Lehigh.EDU (Josh Cohen [890918]) (02/22/91)
Row reducing, dont fret! it can be done and I have just the program to do it.. I got it from wuarchive, i believe... written for the 28s.... ( should work on 48) mail me if you cant get it jcohen@scarecrow.csee.lehigh.edu
pashdown@javelin.es.com (Pete Ashdown) (02/25/91)
jcohen@lehi3b15.csee.Lehigh.EDU (Josh Cohen [890918]) writes: >Row reducing, dont fret! >it can be done and I have just the program to do it.. I got it from >wuarchive, i believe... written for the 28s.... ( should work on 48) >mail me if you cant get it >jcohen@scarecrow.csee.lehigh.edu *SIGH* I posted this a couple of weeks ago. I tried the one for the 28s as well, it works, but it is about three times as big. Here is the program: %%HP: T(3)A(R)F(.); @ RWRD - Matrix Row Reduction ( matrix - reduced matrix ) @ Robert T. Wilson - University of Iowa \<< DUP OBJ\-> OBJ\-> DROP \-> r c \<< r r 1 \-> m n s \<< 1 r START c \->ARRY DEPTH ROLLD NEXT 1 r START DEPTH ROLL NEXT 1 r START 0 's' STO 1 c FOR z IF DUP z GET 0 \=/ THEN z 's' STO c 'z' STO END NEXT IF s 0 > THEN DUP s GET IF 1 \=/ THEN DUP s GET / END 1 r 1 - START r ROLL IF DUP s GET 0 \=/ THEN DUP2 s GET * - 1 'n' STO END SWAP NEXT END r ROLLD NEXT r 'n' STO 1 c FOR z 1 r FOR y IF DUP z GET 1 == THEN n ROLLD 'n' DECR IF 1 == THEN r 'y' STO c 'z' STO END ELSE n ROLLD END NEXT NEXT 1 r START DEPTH ROLLD NEXT 1 r START DEPTH ROLL OBJ\-> DROP NEXT r c 2 \->LIST \->ARRY \>> \>> \>> Works great! Less filling! -- "If the real Jesus Christ were to stand up today He'd be gunned down cold by the CIA" - The The Pete Ashdown pashdown@javelin.sim.es.com ...uunet!javelin.sim.es.com!pashdown