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RPN Program for Eigenvalues?
Message #1 Posted by ┴ngel Martin on 23 Mar 2004, 7:50 a.m.

Hello Math-heads,

I've been looking for an RPN program that calculates all the Eigenvalues for a generic case, NxN square matrix. Tthat is to say not limited to 3x3, or 4x4, etc.

I'd appreciate your hints if you know of such a program being available somewhere.

BTW, the program below will solve for real eigenvalues, but of course won't find complex values, nor there's a fool-proof method (depends on initial guesses, etc. It is nevertheless an interesting example of the power of the advantage matrix functions, combined with solve.

LBL "*VP" STO 00 "IDN" XROM "MIDN" RCL 00 "X" MAT* "IDN,AA,IDN" MAT- "IDN" MDET RTN LBL "EIGEN" "DIM=?" PROMPT "AA" MATDIM XROM "IMR" DIM? "IDN" MATDIM E ENTER^ 50 "*VP" SOLVE "VP=" ARCL X AVIEW END

      
Re: RPN Program for Eigenvalues?
Message #2 Posted by Bill Holes on 23 Mar 2004, 9:35 a.m.,
in response to message #1 by ┴ngel Martin

PPC-TN V1N3 Oct. 1980 may help a bit. A 214 step RPN program to compute all eigenvalues of a real symmetic matrix up to 22 x 22 using Jacobi's method is listed on page 12. I believe it was submitted by Valentin Albillo.

            
Re: RPN Program for Eigenvalues?
Message #3 Posted by ┴ngel Martin on 23 Mar 2004, 10:22 a.m.,
in response to message #2 by Bill Holes

Bill, right on the money! Thanks so much.


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