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Student Support Forum: 'can't get a numerical solution' topicStudent Support Forum > General > Archives > "can't get a numerical solution"

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Nick
07/18/08 11:33am

I want to solve the following equation numerically (apparently there is no analytical solution):


**************************************************
myeqrlx :=
E0 == Integrate[
p[v]*((s[t]/ke)*(UnitStep[v - s[t]/ke]) +
v*(UnitStep[s[t]/ke - v]) +
Integrate[j[t - z]*s'[z]*UnitStep[s[z]/ke - v], {z, 0, t}]), {v,
0, m}]
**************************************************


I am looking for a solution for s[t], so I tried this:


**************************************************
i = NDSolve[{myeqrlx, s[0] == 12.3784}, s, {t, 0, 10}]

Plot[Evaluate[s[t] /. i], {t, 0, 10}, PlotRange -> All]
**************************************************


Which didn't work and I am really in despair now :(
If would be so grateful if anyone could help me.


I was using the following values:


**************************************************
j[t_] := (ke + kc1 +
kc2*(1 - Exp[-(kc2*(ke + kc1))/(eta*(ke + kc1 + kc2))*t]))/((ke +
kc1)*(ke + kc1 + kc2))

p[v_] := a*b*v^(b - 1)*Exp[-a*v^b]

ke := 0.3

kc1 := 0.2

kc2 := 0.9

eta := 1.4

a := 6

b := 4

E0 := 5

m := 2

s[0] := 12.3784
**************************************************




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Subject (listing for 'can't get a numerical solution')
Author Date Posted
can't get a numerical solution Nick 07/18/08 11:33am
Re: can't get a numerical solution Forum Modera... 07/21/08 1:20pm
Re: Re: can't get a numerical solution Nick 07/23/08 2:40pm
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