I do not think that this is 64 bit representation issue: 2^.15^22 85.9516 15(cs&|@^)22 5 3 20 15 18 6 10 11 24 14 9 cs|15(^)22 5 3 20 15 18 0 10 11 0 0 0
I think it's a special code issue. I think the (cs&|@^) expression gets handled by special code. Thanks, -- Raul On Sat, Jul 28, 2018 at 3:59 PM Brian Schott <[email protected]> wrote: > > Chris, (et al), > > Referring to your recommendation regarding issue #1, I am having some > difficulty. > Norman claims that the reason the following computation results in 0's is > that numbers like 15^22 are too big for the computer to represent. But > 15^22 can be represented with a 64bit computer, at least in my J version, > so the 0's do not produce the "signal" that the calculation needs > adjustment. > > cs=.29 > 15(cs&|@^)22 5 3 20 15 18 > 0 10 11 0 0 0 > > However, the subsequent calculation adjustments that are then employed in > the fsoj are all correct as far as I know, and the only thing that I think > needs change is a statement that the revised version (which uses powers > instead of multiplication) requires a few other changes which are all > included in the remaining write up. Such a statement should replace the > calculation above and the explanation of the 0's. > > Maybe there is some other calculation that can be done to signal that a > problem exists, but I could not produce such a calculation. > > Help. > > On Sat, Jul 28, 2018 at 8:00 AM, chris burke <[email protected]> wrote: > > > For 1), please use 2 large primes as suggested to fix this for J64. I think > > any pair should do for this article. > > > > For 2) whether you use f"0 or f&> on a list of numbers is a matter of > > taste, as also whether you include the "0 or &> in the definition or use it > > when it is called. I would leave the style unchanged here, but after the > > sentence "The & conjunction ..." it is worth pointing out that "0 could be > > used to the same effect. > > > > > > On Fri, Jul 27, 2018 at 3:56 PM, Brian Schott <[email protected]> > > wrote: > > > > > I am now working on fsoj 39 about cyphers. There are 2 separate but > > > slightly related issues I need help with. > > > > > > Issue #1) > > > > > > The following code in fsoj produces the result shown. > > > > > > cs=.29 > > > 15(cs&|@^)22 5 3 20 15 18 > > > 0 10 11 0 0 0 > > > > > > But current (64bit) J produces the following result. > > > > > > cs=.29 > > > 15(cs&|@^)22 5 3 20 15 18 > > > 6 10 11 24 14 9 > > > > > > Norman uses the fsoj result to lead into a short description of the > > problem > > > which results and a fix for the problem which involves using the > > following > > > adjustments. > > > > > > Instead of using > > > > > > enc=:cs&|@* > > > > > > Norman uses > > > > > > mul=.cs&|@* > > > eenc=.mul/@# > > > 5 eenc &> 22 5 3 20 15 18 > > > 13 22 11 24 10 15 > > > > > > The issue is that current J does not need the revision, but the rest of > > the > > > fsoj is based on the such a need. I suspect a good alternative would be > > to > > > use a well studied product of 2 large primes in place of the cs=.29 to > > show > > > the problem exists and then use those 2 large primes in place of the 2 > > > Norman uses later in the fsoj article ( 3551=53*67) . > > > > > > Comments on how to handle this question are sought here. If a pair of > > large > > > primes are part of the suggestion, are there well studied or well > > > publicized examples? > > > > > > Issue #2) > > > A smaller detail related to Norman using every (&>) in his development of > > > the solution to the problem above when applying the verb eenc. He > > justifies > > > this choice on eenc NOT being a scalar verb. But if eenc is simply > > defined > > > with rank 0 as > > > > > > > > > eenc=:mul/@#"0 > > > > > > > > > then every is unnecessary. > > > > > > > > > My question is, should the rank 0 version be used instead? > > > > > > -- > > > (B=) <-----my sig > > > Brian Schott > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > -- > (B=) <-----my sig > Brian Schott > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
