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I am trying to plot a solution to the heat equation

$u(x,t) = \sum_1^\infty \frac{8(-1)^(n+1)}{\pi^2 n^2} \sin(n \pi x) \exp(-n^2 \pi^2) $

I am using the following from another answer here on Mathematica. I am trying to plot it from x=[0,1]. I am trying the following, but it does not seem to produce a plot

f[x_, t_, nm_] := SUM[(8 (-1)^(n + 1)/(Pi^2*n^2))*Sin[n* Pi *x]*Exp[-n^2 Pi^2*t], {n, 1, nm}];

Plot[Table[f[x, t, 150], {t, {0, 0.01, 0.1, 0.5, 1, 10}}] // Release, {x, 0, 1, 0.05}]
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closed as too localized by Jens, Artes, Verbeia Jan 26 '13 at 22:42

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It produces a plot for me: Wolfram Mathematica 9. I think you mistyped the SUM. The correct is Sum. – m0nhawk Jan 26 '13 at 20:19
In addition to what @m0nhawk said, you also have a syntax error in Plot. Replace // Release, {x, 0, 1, 0.05} by // Evaluate, {x, 0, 1} – Jens Jan 26 '13 at 20:23
up vote 5 down vote accepted

You have several syntax (and non-syntax) errors. Check for them:

f[x_, t_, nm_] := Sum[(8 (-1)^(n + 1)/(Pi^2*n^2))*Sin[n*Pi*x]*Exp[-n^2 Pi^2*t], {n, 1,nm}];
Plot[Evaluate@Table[f[x, t, 150], {t, {0, 0.01, 0.1, 0.5, 1, 10}}], {x, 0, 1}, PlotRange -> Full]

Mathematica graphics

You may find this list of tips on syntax useful.


Perhaps you could use the following:

Plot3D[f[x, t, 30], {t, 0, .3}, {x, 0, 1}, PlotRange -> Full, 
         AxesLabel -> {"Time", "x", "Temp"}, 
         LabelStyle -> Directive[12, Bold]]

Mathematica graphics

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@Verbeia Hey! That's a very good idea! – Dr. belisarius Jan 26 '13 at 22:45
Do you guys know how I can plot legends automatically so that it will indicate appropriate time for my solution. – l3win Jan 31 '13 at 0:07

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