We have seen in class an example of a discrete random variable,
where the values are dense in the unit interval. The distribution
function is a devilish stair: when climbing it up, one has to take
in any time interval infinitely many steps. Here is my
Mathematica program, which draws the stair. The Deepneslevel
measures, how devilish you want to make the stair.
DevilSkin := {Line[{{0,0},{1,0}}]};
Hair[n_]:=Table[Line[{{(2k-1)/2^n,0},{(2k-1)/2^n,2/4^n}}],{k,2^(n-1)}];
DevilHair:=Show[Graphics[{DevilSkin,Table[Hair[n],{n,DeepnesLevel}]}],
PlotRange->{{0,1},{0,2}},DisplayFunction->Identity];
LevelValues[n_]:=Table[{(2k-1)/2^n,2/4^n},{k,2^(n-1)}];
UpToLevel[nn_]:=Sort[Module[{s={}}, Do[s=Union[s,LevelValues[n]],{n,nn}];s]];
DevilStair[x_]:=Module[{v=.0},Do[If[u[[k,1]]<=x,v=v+u[[k,2]]],{k,Length[u]}];v];
DevilStairCase :=Plot[DevilStair[x],{x,0,1},DisplayFunction->Identity];
HellsBells[DL_]:=Module[{}, DeepnesLevel=DL; u=UpToLevel[DeepnesLevel];
Show[GraphicsArray[{DevilHair, DevilStairCase}],
DisplayFunction->$DisplayFunction]];
Display["!psfix -land>devilstair.ps",HellsBells[6]];