(* FT cviceni 22.10.2013 *)

ft[s_, t_, v_]:=FourierTransform[s,t,v,FourierParameters->{0, -2 Pi}];

ft[1, t, v]

ft[t, t, v]

dt = 0.01; dx = 0.05; n = 40; 
f[a_, b_, c_] := b + 0.5 (a - 2 b + c) dt/dx^2;
ff[u_]:=Table[f[u[[1+Mod[i-1,n]]],u[[i]],u[[1+Mod[i+1,n]]]],{i,1,n}]
u0 = RandomReal[1, n];
uu = NestList [ff, u0, 5];
ListPlot3D[uu]

dx=0.11;