His narration states Quote: “Imagine a room full of 100 people with 100 dollars each. With every tick of the clock, every person with money gives a dollar to one randomly chosen other person. After some time progresses, how will the money be distributed?”
And I came up with this simulation. (45 people with 45 dollars each, same as on the webpage.) On Mon, Jul 10, 2017 at 5:51 PM, Raul Miller <rauldmil...@gmail.com> wrote: > Why do you think that? > > Or were you referring to Xiao-Yong Jin's narrative? > > Thanks, > > -- > Raul > > On Mon, Jul 10, 2017 at 5:17 PM, Devon McCormick <devon...@gmail.com> > wrote: > > So, you start with $10,000 (=100*$100) but end up with $2,025 (=45*$45), > > how? > > > > On Mon, Jul 10, 2017 at 3:59 PM, Raul Miller <rauldmil...@gmail.com> > wrote: > > > >> I don't really understand what you mean by "mean expectations" - could > >> you describe the intent there? > >> > >> That said, here's how far I've gotten in implementing this concept: > >> > >> tick=: (0 >. <:) + i.@# +/@:(=/)~ +/@:* ?@# # > >> (mean,stddev)"1 tick^:(i.10)]100#100 > >> 100 0 > >> 100 0.932034 > >> 100 1.41421 > >> 100 1.91749 > >> 100 2.07437 > >> 100 2.34844 > >> 100 2.48633 > >> 100 2.71546 > >> 100 2.97803 > >> 100 3.26289 > >> > >> (Also, for animation in J, there's actually a lot of options... > >> basically though you set up a paint event which calls into your > >> rendering code and then trigger updates from systimer.) > >> > >> Thanks, > >> > >> -- > >> Raul > >> > >> On Mon, Jul 10, 2017 at 3:43 PM, Xiao-Yong Jin <jinxiaoy...@gmail.com> > >> wrote: > >> > I thought this is a good lunch break exercise. > >> > > >> > http://www.decisionsciencenews.com/2017/06/19/counterintuitive- > >> problem-everyone-room-keeps-giving-dollars-random-others- > >> youll-never-guess-happens-next/ > >> > > >> > Quote: “Imagine a room full of 100 people with 100 dollars each. With > >> every tick of the clock, every person with money gives a dollar to one > >> randomly chosen other person. After some time progresses, how will the > >> money be distributed?” > >> > > >> > And I came up with this simulation. (45 people with 45 dollars each, > >> same as on the webpage.) > >> > > >> > /:~@(-&1`]@.(=&0)"0 (#/.~@] + ~.@]{[)`(~.@])`[} >&0 # (?@#~@#@]`]`[} > >> ]I.@:=i.@#)^:_@?@#~@#)^:5000 #~45 > >> > > >> > And I really like to see the mean expectations and the standard > >> deviation of the mean, I ended up doing this. (Make sure the J > sentence is > >> one long line if you want to try it out.) > >> > > >> > ((],.[:(+/%#*<:@#)&.:*: -"1)+/%#)}.(/:~@(-&1`]@.(=&0)"0 (#/.~@] + > >> ~.@]{[)`(~.@])`[} >&0 # (?@#~@#@]`]`[} ]I.@:=i.@#)^:_@?@#~@#)^:10000) > ^:(<65) > >> #~45 > >> > 0.984375 0.124984 > >> > 2.01562 0.170335 > >> > 3.0625 0.180765 > >> > 4.15625 0.230616 > >> > 5.21875 0.248476 > >> > 6.1875 0.306894 > >> > 7.35938 0.332862 > >> > 8.64062 0.362809 > >> > 9.84375 0.380723 > >> > 10.9688 0.383805 > >> > 12.125 0.407944 > >> > 13.6406 0.423964 > >> > 15.0625 0.457453 > >> > 16.5312 0.462893 > >> > 18.1875 0.480717 > >> > 19.7031 0.464877 > >> > 21.1562 0.475709 > >> > 22.7031 0.483702 > >> > 24.4062 0.516935 > >> > 26.4062 0.5768 > >> > 28.1094 0.604266 > >> > 29.8281 0.617838 > >> > 31.875 0.61942 > >> > 33.9375 0.603345 > >> > 35.7812 0.642211 > >> > 37.9844 0.647987 > >> > 40.6562 0.731321 > >> > 43 0.739342 > >> > 45.3906 0.723616 > >> > 48.0469 0.7613 > >> > 51.6094 0.823639 > >> > 54.7656 0.873934 > >> > 57.1406 0.815544 > >> > 60 0.866598 > >> > 63.8594 0.898319 > >> > 68.75 0.918018 > >> > 73.5781 1.00736 > >> > 78.3281 1.08128 > >> > 84.9688 1.25534 > >> > 93.4688 1.29731 > >> > 104.578 1.73274 > >> > 114.922 2.07574 > >> > 131.938 2.7357 > >> > 159.359 4.40899 > >> > 204.766 7.24239 > >> > > >> > So, how do I make a fancy animation (like the one in the webpage I > >> linked in the beginning of this message) with J? > >> > ------------------------------------------------------------ > ---------- > >> > For information about J forums see http://www.jsoftware.com/ > forums.htm > >> ---------------------------------------------------------------------- > >> For information about J forums see http://www.jsoftware.com/forums.htm > >> > > > > > > > > -- > > > > Devon McCormick, CFA > > > > Quantitative Consultant > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA Quantitative Consultant ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
