Out of memory issue in Matlab 7.6 (R2008a)

I am using Matlab 7.6.0(R2008a) to simulate a state space model (control system).

System matrix param: A=[-12.5 1 0; -38 0 1; -16 0 0] (3x3) and B=[0; -117190; 937520] (3x1).

When I run this state space model with ode45, matlab shows " Error using horzcat, Out of memory " problem after 20 mts of simulation, where as when I changed B to smaller value say B=[0; -10; 93], it works fine. I tried to solve the problem by increasing virtual memory = ram, but it didn't do anything better. To alter the memory allotted for JVM, there is no jvm option seen under the matlab preference header. The same problem continues in simulink model also.

Please give some tips to sort out this problem.

Thanks,

Baburaj

Answer 1

[Titus Edelhofer]

Hi,

this is my guess (!): the values in B have an influence on the stiffness of the system. Does the ode45 makes very small time steps? If this is the case I would suggest to try one of the stiff solvers like ode15s or ode23s, ode23t.

Titus