Update the variables in ODE routines?

Hi everyone,

I have a question concerning the ODE routines. I should model a complicated nonlinear dynamic system in time domain using ode113 (or any other one). I want to ask if it is possible to update the (by derivatives) predicted variables by easily replacing the optimized value in current time step? eg. we have the Y_1 as the variable in first time step and dY_1 its derivative can we update Y_2 while calculating dY_2 just buy putting Y_2 = .... ?

tnx all

[Torsten]

????

Answer 1

[Andrew Schenk]

The purpose of the ODE solver is to solve for the values of Y given a MATLAB function which provides values of dY. If you want to calculate the value of Y at a given step, the ODE solver does not need to solve for it.

You could accomplish this by removing Y2 as a variable from ode113 and instead use a persistent variable in your MATLAB function to calculate Y2 and track the past states.