b [: -. [: */\@:-. [: %&365 i. NB. taking away the needless adjustment for leap years (0, }:b 365) -: -. ([: */ 365 %~ 365-i.)"0 i. 365 NB. comparing it to Rogers solution in the J Wiki 1 100 (6)!:2 'b 365' 2.17831e_5 100 (6)!:2 '-. ([: */ 365 %~ 365-i.)"0 i. 365' 0.00222781
On Wed, Jan 18, 2012 at 2:15 PM, Pablo Landherr <pablo.landh...@gmail.com>wrote: > Another solution. > > bdayprob > [: -. [: */\@:-. [: %&365.25 i. > bdayprob 24 > 0 0.00273785 0.00819856 0.0163448 0.0271172 0.0404352 0.0561981 0.074286 > 0.0945617 0.116872 0.141051 0.166919 0.19429 0.222967 0.25275 0.283438 > 0.314827 0.346718 0.378912 0.411221 0.443461 0.475459 0.507053 0.538094 > > > > > On Wed, Jan 18, 2012 at 7:03 AM, Roger Hui <rogerhui.can...@gmail.com>wrote: > >> Does http://www.jsoftware.com/jwiki/Essays/Birthday%20Problem answer any >> of >> your questions? >> >> >> >> On Tue, Jan 17, 2012 at 9:40 PM, Linda Alvord <lindaalv...@verizon.net >> >wrote: >> >> > Capture the last row of c >> > >> > ]l=:{:c >> > 106 249 7 326 308 274 81 347 276 113 108 20... >> > >> > And use grade up to arrange the numbers in sequence >> > >> > (/:l){l >> > 0 1 3 3 4 4 5 5 6 6 7 7 7 7 8 8 8 13 13... >> > >> > This should be i.365 >> > >> > I have an idea on how to get what you want but I'll wait to see what >> you do >> > next. >> > I have to use a deal without a fixed seed for the deal. >> > >> > I happened to remember 24 and haven't gone looking for the number and >> > haven't the foggiest notion of how I proved it! >> > >> > Linda >> > >> > -----Original Message----- >> > From: Linda Alvord [mailto:lindaalv...@verizon.net] >> > Sent: Tuesday, January 17, 2012 11:25 PM >> > To: 'Programming forum' >> > Subject: RE: [Jprogramming] Challenge 4 Bountiful Birthdays >> > >> > I think we need sortleaf. >> > >> > Linda >> > >> > -----Original Message----- >> > From: programming-boun...@jsoftware.com >> > [mailto:programming-boun...@jsoftware.com] On Behalf Of Brian Schott >> > Sent: Tuesday, January 17, 2012 10:14 PM >> > To: Programming forum >> > Subject: Re: [Jprogramming] Challenge 4 Bountiful Birthdays >> > >> > $c=.500 365?.@$365 >> > $D=. i.&0"1(=&#~.)\"1 c >> > mean D+1 NB. 25.086 >> > pretty 5 SL sortleaf 1+D >> > >> > $c=. 10 500 365?.@$365 >> > $D=. i.&0"1(=&#~.)\"1 c >> > mean, D+1. NB. 24.6856 >> > pretty"2] 5 SL"0 1 sortleaf"1] 1+D >> > >> > I am suspicious of these results because my memory is that the mean is >> > closer to 18.5 people. Then again, other measures of the center look >> closer >> > to 19, just looking at the stemplots. >> > >> > --- >> > (B=) >> > >> > On Jan 15, 2012, at 5:40 AM, "Linda Alvord" <lindaalv...@verizon.net> >> > wrote: >> > >> > > >> > > For this challenge, as usual, do not use @ but you may use whatever >> > style >> > > and strategy you like to accomplish the task. >> > > >> > > >> > > >> > > The problem is to simulate the classic birthday problem. >> > > >> > > >> > > >> > > A single trial works this way. People enter a room one by one and >> > declare >> > > their birth date. Suppose the 29th person is the first person to >> match a >> > > birthday of someone in the room. The result of the first trial is 29. >> > > >> > > >> > > >> > > Repeat for 500 trials. >> > > >> > > >> > > >> > > If you use Kip's frequency distribution of the results you have lots >> of >> > > information. >> > > >> > > >> > > >> > > fd=:[: /:~ ~. ,. [: +/"1 ~. =/ ] >> > > >> > > >> > > >> > > But the mean gives a more concise summary of the data. So, the final >> > part >> > > of the problem is to obtain a list of 10 means of 500 trials and >> the >> > > mean of the means. >> > >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
