Re: [math-fun] math-fun Digest, Vol 159, Issue 58
--ok, I immediately see from that last URL that you did it wrong. A0 to A1 looks reasonable. A1 to A2 is already wrong because note row #2 was left unaltered (should have changed) but row #1 changed (should have been unaltered).
(1) Steps A0 to A2 operate on rows 3 and 4, not 1 and 2 .
(2) My program executes the sequence you specified as follows --- 7 4 8 2 5 9 1 3 6 ...
I did previously point out this elementary malfunction, which is the responsibility of the designer rather than the programmer. Once an A_ij to be cleared is specified, Givens' R_ij alters rows & cols i,j , intentionally or otherwise!
--WRONG!! It alters rows i and j only, and in ALL columns simultaneously!
(3) I did however summon the initiative to investigate alternative scanning sequences: NW instead of SE along diagonals, and inwards rather than outwards. Unsurprisingly, they fail as well.
[In fact, I still find it rather surprising that scanning columns does work --- as you point out elsewhere, both N-ward and S-ward versions.]
--you continue to be confused... -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)
I slipped up there --- thankyou. Fortunately for me, Maple gets it right. WFL On 5/20/16, Warren D Smith <warren.wds@gmail.com> wrote:
--ok, I immediately see from that last URL that you did it wrong. A0 to A1 looks reasonable. A1 to A2 is already wrong because note row #2 was left unaltered (should have changed) but row #1 changed (should have been unaltered).
(1) Steps A0 to A2 operate on rows 3 and 4, not 1 and 2 .
(2) My program executes the sequence you specified as follows --- 7 4 8 2 5 9 1 3 6 ...
I did previously point out this elementary malfunction, which is the responsibility of the designer rather than the programmer. Once an A_ij to be cleared is specified, Givens' R_ij alters rows & cols i,j , intentionally or otherwise!
--WRONG!! It alters rows i and j only, and in ALL columns simultaneously!
(3) I did however summon the initiative to investigate alternative scanning sequences: NW instead of SE along diagonals, and inwards rather than outwards. Unsurprisingly, they fail as well.
[In fact, I still find it rather surprising that scanning columns does work --- as you point out elsewhere, both N-ward and S-ward versions.]
--you continue to be confused...
-- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)
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Warren D Smith