[math-fun] maxdet circulants, Clark's issues
WE CLARK: Starting at N = 29 using the values of -1 and + 1 given by Warren and using Maple with Digits = 1000, I get different values when I round his determinants to the nearest integer.
--good. My values were inexact.
For example, for N = 29 I get Maple's value = -668472148627227148288 Warren's value = 668472148627227148000 It seems that in Warren's numbers there are not enough significant digits above N = 28.
--true.
Also in the case of N = 29 I get a different sign for the determinant.
--above 28 I printed out |det| not det. --Note: It is conceivable, but highly unlikely, that my maxdet circulants are not really maxdet, because there is some other one with a determinant like 1.00000000001X higher. I doubt that pathology has happened but it might be a concern if this table were extended further to say N=50 or 60, and I cannot promise with 100% certainty that it did not happen already. Of course it would be possible to enhance my program to overcome these quibbles, but I did not. --If Clark has computed all the exact integer values via MAPLE, please email them to me warren.wds AT gmail.com
Here's what I got for N > 28: 29 -668472148627227148288 30 5815090244206769209344 31 73063423016960000000000 32 607251019095909989351424 33 -6839365759938434944729088 34 -44960394053009336168349696 35 -573365205894336707192422400 36 -6807508522480635921404264448 37 -54110675162696323264893943808 38 439152787578280613557573779456 39 6321982650569688652881686691840 40 64398429946593839846774588571648 On Fri, Aug 31, 2012 at 3:29 PM, Warren Smith <warren.wds@gmail.com> wrote:
WE CLARK: Starting at N = 29 using the values of -1 and + 1 given by Warren and using Maple with Digits = 1000, I get different values when I round his determinants to the nearest integer.
--good. My values were inexact.
For example, for N = 29 I get Maple's value = -668472148627227148288 Warren's value = 668472148627227148000 It seems that in Warren's numbers there are not enough significant digits above N = 28.
--true.
Also in the case of N = 29 I get a different sign for the determinant.
--above 28 I printed out |det| not det.
--Note: It is conceivable, but highly unlikely, that my maxdet circulants are not really maxdet, because there is some other one with a determinant like 1.00000000001X higher. I doubt that pathology has happened but it might be a concern if this table were extended further to say N=50 or 60, and I cannot promise with 100% certainty that it did not happen already.
Of course it would be possible to enhance my program to overcome these quibbles, but I did not.
--If Clark has computed all the exact integer values via MAPLE, please email them to me warren.wds AT gmail.com
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
On 8/31/12, W. Edwin Clark <wclark@mail.usf.edu> wrote:
Here's what I got for N > 28:
29 -668472148627227148288 30 5815090244206769209344 31 73063423016960000000000 32 607251019095909989351424 33 -6839365759938434944729088 34 -44960394053009336168349696 35 -573365205894336707192422400 36 -6807508522480635921404264448 37 -54110675162696323264893943808 38 439152787578280613557573779456 39 6321982650569688652881686691840 40 64398429946593839846774588571648
--Clark's exact values agree exactly with my current (integer form) output for N<=31; only disagreements when N>=32. Of course, this exact agreement could have been just by luck in the last few cases.
participants (2)
-
W. Edwin Clark -
Warren Smith