Warning: Failure at t=6.160957e+02. Unable to meet integration tolerances without reducing the step size below the smallest value allowed (1.818989e-12) at time t.
1 4
Unable to perform assignment because the size of the left side is 71-by-4 and the size of the right side is 1-by-4.
@Sveta, I just want to check the stability of the original system with some random initial conditions. So far, I haven't encountered any integration failure messages in this relatively simple code. I prefer to include the fixed parameters inside the ODE function for easy reference. Which parameters do you intend to change during the integration?
at the beginning of your program to make the code work because the above global variables were not available.
In some phase of your code run, the integrator is no longer able to integrate your system of differential equations and gives up with the error message
Warning: Failure at t=6.160957e+02. Unable to meet integration tolerances without reducing the step size below the smallest value allowed (1.818989e-12) at time t.
After each call of the integrator, you expect an array of size (71x4) as result and you want to save it into a different array. But since the integrator stops already at time 616,.. , the (71x4) array is not available and you make an assignment that would only have been possible if the integrator had succeeded. This gives the error message
Unable to perform assignment because the size of the left side is 71-by-4 and the size of the right side is 1-by-4.
and MATLAB stops.
I cannot help you in this respect since the error stems from the integration of your model equation that I don't know.
thanks for your message. I sow matLAB has settled on integration. it is a problem of the function of Matlab - ode45 or ode15s. Maybe is it possible to change them to another function or to change set of parameters in options?
I try to solve it too much time and cannot to find something good...