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Topic: complex results using ODE45
Replies: 3   Last Post: Oct 22, 2013 2:25 PM

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Jeffrey

Posts: 3
Registered: 10/15/13
complex results using ODE45
Posted: Oct 15, 2013 1:53 PM
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I have the two m files given below. "a" and "T" are returned as complex with the coefficient of the complex part being zero (the real part gives the correct answer and hence the plot is fine) . Also dadT is becoming complex.

Why are values becoming complex?

Please help.

Jeff
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%this is in file alpha.m
function dadT = alpha(T,a)
b = 20
l= 50.1
k=exp(l)
ner = -36108.73
n=1.269
dadT = (k/b)*(exp(ner/T)) *((1-a)^n
________________________________________

%this is in file alpha_ode45.m
clear
T0 = 0.00255
Tspan = [653.25,773]
[T,a] = ode45(@alpha,Tspan,T0);

% Print display in command window
disp('Solution, T and alpha')
format short
[T a]

% plot a vs T
plot(T,a)
axis([600 800 0 1])
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