[R] Differential problem

[Berend Hasselman]

On 11-07-2013, at 09:13, Raphaëlle Carraud <raphaelle.carraud at oc-metalchem.com> wrote:

> Hello,
> 
> I have the following differential equation system to solve, the variables I wish to obtain being A, B, C, D, E, I, G and H.
> 
>    0 = -dA + dB + 2*dC - 2*r1 - 2*r5
>    0 = dA + dD + r1 + r4
>    0 = K2 - C/B^2
>    0 = K3 - D/(A*B)
> 
>    0 = r5 + 2*r4 - dE
>    0 = r5 -dI
>    0 = -r5 - r4 - dG
>    0 = -r1/2 - dH
> 
> r1, r4 and r5 are variables expressed as functions of A, B, C, D, I, G and H, calculated previously in the integrated function. K2 and K3 are parameters.
> 
> As I have two algebraic equations, I think this system is a DAE (Algebraic differential equation). I found in the package deSolve two functions that resolve DAE but I didn't manage to obtain a solution; it says that the variable dA cannot be found.
> 

Show us your script where you define the function and run the DAE solver. Without that nobody can provide an answer.

Berend.

> Does anyone know how to solve this problem?
> 
> Thank you
> 
> Raphaëlle Carraud
> 
> 
> Raphaëlle Carraud
> 
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> 
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