news article for your approval
- To: mathgroup at smc.vnet.net
- Subject: [mg2844] news article for your approval
- From: EmiNet Domain News Admin <news at emi.net>
- Date: Sat, 23 Dec 1995 03:20:41 -0500
>From: drc at emi.net (David Cabana)
>To: mathgroup at smc.vnet.net
>Subject: what's wrong w this animation?
>Organization: EmiNet Domain Internet Services (407)731-0222
I am reading Gaylord and Wellin's "Computer Simulations with Mathematica".
I am having trouble with some of the code on the accompanying cd. They
define a two-dimensional random walk as follows:
Walk2D[n_] :=
Module[{moves, randomChoices},
directions = {{0,1}, {1,0}, {0,-1}, {-1,0}};
randomChoices = Table[Random[Integer, {1, 4}], {n}];
FoldList[Plus, {0,0}, directions[[randomChoices]] ]
]
Actually, I modified their definition by introducing a couple of local
variables to enhance readability. That code works well; the trouble
starts when I try to use their code for animating the walk.
AnimateWalk2D[coords_, opts___]:=
Map[Show[Graphics[{
{RGBColor[1,0,0],PointSize[.1],
Point[ coords[[#]] ]},
Line[Take[coords, #]]}],
opts,
AspectRatio -> Automatic,
PlotRange -> Map[{Min[#]-.2, Max[#]+.2}&,
Transpose[coords]]]&,
Range[2, Length[coords]]]
When I run
AnimateWalk2D[ Walk2D[10] ]
I get 10 separate images rather than an animation. What's wrong?
--
David Cabana drc at gate.net
"To stand in silence when they should be protesting makes cowards of men."
Abraham Lincoln