How to collect the calculation history during the solving of ODE's

Hi,

I am solving a set of eight 1st order ODE's. The actual differential equations have been defined in a separate function (obviously), but besides these main equations, there are several other calculation steps which are performed within that function.

Question: The ODE-solver only returns the numerical solution of the ode's. is there any way to collect all the other output which is generated during each iteration step?

Short simplified overview of my model (final output is C, R links to another function, which also has C as variable):

poly=(C(1)+C(2)+C(4)+C(5))/2; xv=(P.*y)./(P.*g);

B=(poly/(1-sum(xv)));

dcdz(1)=-2*R(1);

(...)

dcdz(6)=R(1)-R(4)-(C(6)-B(1));

dcdz(7)=R(7)+R(8)-(C(7)-B(2));

dcdz(8)=R(4)+R(5)-(C(8)-B(3));

In this case, I am interested in the values of B. The program executes this function for each iteration step, so B is calculated every time. I can see them in the command window when I remove the semicolon, but so far, I have been unable to collect the values of B in an array.

Any suggestions?

Thanks,

Wikke den Hartogh

Answer 1

[Andrew Newell]

If you just want the value of B at each point in the solution, you could calculate it afterwards using a function that inputs C and outputs B.

[Wikke den Hartogh]

I'd be doing the calculations twice then, but yeah it should work. Thanks!