"Nasser M. Abbasi" <nma@12000.org> wrote in message <js8eh4$6et$1@speranza.aioe.org>...
> On 6/24/2012 7:59 PM, Sriraam wrote:
> > Could someone please elaborate on how to use ODE 15s or 45 for this differential equation?
> >
> > (1/beta) *(d alpha/dT) = ln A*(1alpha) (E/RT)
> >
> > I have the value of alpha and E as a function of a.
> >
> > I need to generate graph of alpha Vs Temperature and d alpha/dT versus Temperature.
> >
>
> Just like you would do with any ode.
>
> Need to write you differential equation in the form
>
> y' = f(t,y)
>
> The function f(t,y) is what is called the "ode function". The
> thing you put as first argument to ode45 call, as in
>
> [t,y]=ode45(@f,[t0 tfinal],initial_conditions);
>
> so, it is your job to first express your ode system in the
> the form y'=f(t,y). Matlab will not do that part for you. Need
> paper and pencil for that. Even if your original ode was not
> first order, need to convert everything to first order
> ode's.
>
> once you do that, then you can code it. In the above, y is
> called the dependent variable, and 't' is the independent
> variable.
>
> see help for many examples.
>
> Nasser
Thank you for your suggestion. I am sorry, I am really a beginner in MATLAB while I understand the ODE.
My ode will be d(alpha)/dt = A exp (E/R*T))(1alpha). ie y'=f(y,T) and T=To+beta*t
Here is when it gets complicated. I need the alpha values with respect to temperature. So A and E I can provide as input at each alpha.
