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Question: Help needed!

Question:Help needed!

RevJB 36 Maple
error plot graph
March 30 2010
0
Hey guys i am currently attempting to do some modelling with maple, i need to solve a PDE system, i am using the following code and am confused with the error i'm getting. restart: M[Star]:=2*10^30: M[planet]:=2*10^27: q:=(M[planet])/(M[Star]): g:=sqrt((R-a)^(2)): H:=0.0333*R^(1): Delta[p]:=H: Alpha := unapply(piecewise(R <> a, 6.67*q^2*10^(-11)*M[Star]*(a/Delta[p])^4/(2*R), R = a, 1), R, a) PDE1:=(∂)/(∂t) S(R,t)=(3 ((∂)/(∂R) (R^((1)/(2)) ((∂)/(∂R) (S(R,t) R^((1)/(2))-(2 Alpha(R,a) (S(R,t))^(3/(2)))/((6.67 10^(-11) M[Star])^((1)/(2))))))))/(R): f(R):=((e)^(-((R-1)^(2))/(2(0.01)^(2))))/(0.01(2 Pi)^(1/(2))); a:=0.5; H:=1.0; IBC := {S(99, t) = 0, S(0.1e-1, t) = 0, S(R, 0) = f(R)}; eval(PDE1); PDE2 := subs(Float(undefined) = 0, eval(PDE1)); pds1 := pdsolve(PDE2, IBC, numeric, S(R, t), time = t, range = 0.1e-1 .. 99, spacestep = 0.1e-1, timestep = 0.25e-4); p0 := pds1:-plot(S, t = 0, R = 0.1e-1 .. 99, color = pink); p1 := pds1:-plot(S, t = 0.1667e-3, R = 0.1e-1 .. 99, color = green); p2 := pds1:-plot(S, t = 0.6667e-3, R = 0.1e-1 .. 99, color = blue); p3 := pds1:-plot(S, t = 0.2667e-1, R = 0.1e-1 .. 99, color = red); p4 := pds1:-plot(S, t = 0.10667e-1, R = 0.1e-1 .. 99, color = orange); p5 := pds1:-plot(S, t = 0.42667e-1, R = 0.1e-1 .. 99, color = brown); plots[display]({p0, p1, p2, p3, p4, p5}); After running this through maple everything runs through up until the point at which i get the equation to solve, the code returns the "module" output as expected but upon asking maple to plot the graphs i get the following error: Error, (in pdsolve/numeric/plot) unable to compute solution for t
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