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NDSolve with arrays

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  • Subject: [mg89203] NDSolve with arrays
  • From: svend <domdey at>
  • Date: Thu, 29 May 2008 07:04:05 -0400 (EDT)

hi all,
i want to solve a PDE by discretizing in one variable in an array and solve. the equations are of the following type:
n = 10;
x0 = 1;
x1 = 10;

play[x_] := IntegerPart[x]

eq1 := {D[f[j][x], x] == f[play[x]][x], f[j][x0] == j^2}

eqs = Flatten[Table[eq1, {j, 1, n}]]
fun = Flatten[Table[f[j], {j, 1, n}]];
tes = NDSolve[eqs, fun, {x, x0, x1}][[1]];

my problem is that the variable x, in which the equation is differential, also appears on the rhs in the "index" of my array. mathematica does not evaluate "play[x]" during NDSolve and just tells me that the rhs is not numerical. I tried "_NumericQ" and similar things but nothing seems. I would be very happy if someone could tell me how to resolve this.


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