Thanks. Linda -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Raul Miller Sent: Saturday, October 17, 2015 11:33 PM To: Programming forum Subject: Re: [Jprogramming] Finding prime palindromes
You left out a value for y. Thanks, -- Raul On Sat, Oct 17, 2015 at 9:47 PM, Linda A Alvord <[email protected]> wrote: > I tried "trace" to see what would happen to g. The results are strange. > > require'trace' > f=: 13 :'":,.p:y' > g=: 13 :'((1=+/"1 (f y)~:'' '')+((1{"1 f y)=2{"1 f y)+(3=+/"1 (f > y)=|:|.|:f y))#f y' > g i.40 > 2 > 3 > 5 > 7 > 11 > 101 > 131 > 151 > f > [: ": [: ,. p: > g > ((1 = [: +/"1 ' ' ~: f) + ((1 {"1 f) = 2 {"1 f) + 3 = [: +/"1 f = [: |: [: > |. [: |: f) # f > > trace '[: ": [: ,. p:' > --------------- 5 Trident ---- > [: > ,. > p: > [: ,. p: > --------------- 5 Trident ---- > [: > ": > [: ,. p: > [: ": [: ,. p: > ============================== > > trace '((1 = [: +/"1 ' ' ~: f) + ((1 {"1 f) = 2 {"1 f) + 3 = [: > +/"1 f = > [: |: [: |. [: |: f) # f' > --------------- 3 Adverb ----- > + > / > +/ > --------------- 4 Conj ------- > +/ > " > 1 > +/"1 > --------------- 5 Trident ---- > = > [: > +/"1 > = [: +/"1 > --------------- 6 Bident ----- > 1 > = [: +/"1 > |syntax error: executet > | t_z=. (1)(=[:+/"1) > > linda > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Linda A > Alvord > Sent: Friday, October 16, 2015 11:31 PM > To: [email protected] > Subject: Re: [Jprogramming] Finding prime palindromes > > Kip, That was a challenge! Soon someone will do it much more grcefully! > Simplifications welcome. It is all done in characters. > > > > f=:[: ": [: ,. p: > > > > g=:((1 = [: +/"1 ' ' ~: f) + ((1 {"1 f) = 2 {"1 f) + 3 = [: +/"1 f = [: |: > [: |. [: |: f) # f > > > > g i.40 > > 2 > > 3 > > 5 > > 7 > > 11 > > 101 > > 131 > > 151 > > > > Linda > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of bill > lam > Sent: Friday, October 16, 2015 2:05 AM > To: Programming forum > Subject: Re: [Jprogramming] Finding prime palindromes > > > > IIRC J extended precision number implementation uses decimal base 1000 > or > > 100000 , so that ": format is fast but calculation is slower. Things > could be the opposite if J had used 2^n base. > > ---------------------------------------------------------------------- > > For information about J forums see > <http://www.jsoftware.com/forums.htm> > http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
