RE: i dont understand module.
- To: mathgroup at smc.vnet.net
- Subject: [mg46546] RE: [mg46542] i dont understand module.
- From: "David Park" <djmp at earthlink.net>
- Date: Mon, 23 Feb 2004 02:15:38 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Sean, If you have multiple statements in a Module, you have to separate them with a ";". Just put a ";" after the sol = ... statement and it will work. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: sean kim [mailto:sean_incali at yahoo.com] To: mathgroup at smc.vnet.net hello goup. I just don't get this. this code was posted while back by Bob Hanlon. All i did was to flank the routine by a module. i did so to minimize memory used. I was hoping that by keepign things local, i can minimize the resources used in the routine. In[1]:= Needs["Graphics`"]; Module[{}, sol=NDSolve[{a'[t]==-0.1` a[t] x[t], b'[t]==-0.05` b[t] y[t], x'[t]==-0.1` a[t] x[t]+0.05` b[t] y[t], y'[t]==0.1` a[t] x[t]-0.05` b[t] y[t], a[0]==1,b[0]==1,x[0]==1, y[0]==0}, {a,b,x,y},{t,0,250}][[1]] Plot[Evaluate[#[[2]][t]& /@ sol],{t,0,250}, PlotStyle->Table[Hue[(k+1)/6],{k,4}], Frame->True, Axes->False, PlotLegend->(#[[1]]& /@ sol), LegendPosition->{1,-.35}, LegendShadow->{0, 0} , ImageSize->400]; ] above fails with the following error. Plot::plnr: sol is not a machine-size real number at t = \ 0.000010416666666666666`. if i flank the module with Do loop, then I get recursion errors In[5]:= Needs["Graphics`"]; Do[ Module[{}, sol=NDSolve[{a'[t]==-0.1` a[t] x[t], b'[t]==-0.05` b[t] y[t], x'[t]==-0.1` a[t] x[t]+0.05` b[t] y[t], y'[t]==0.1` a[t] x[t]-0.05` b[t] y[t], a[0]==1,b[0]==1, x[0]==1,y[0]==0}, {a,b,x,y},{t,0,250}][[1]] Plot[Evaluate[#[[2]][t]& /@ sol],{t,0,250}, PlotStyle->Table[Hue[(k+1)/6],{k,4}], Frame->True, Axes->False, PlotLegend->(#[[1]]& /@ sol), LegendPosition->{1,-.35}, LegendShadow->{0, 0} , ImageSize->400]; ], {iteration, 10}] $RecursionLimit::reclim: Recursion depth of 256 exceeded. what's going on here? and how do i fix it so that i can run it automatically? thanks all in advance. sean