Changing Tf in standalone integrator

jerluen · July 6, 2022, 6:57am

Hi,

Is there any way to change the final integration time in a standalone integrator?
In the Python interface the setter function allows these options [‘p’, ‘S_adj’, ‘T’, ‘x’, ‘u’, ‘xdot’, ‘z’].

However, attempting to set ‘T’ will result in

error: sim_dims_get_from_attr: field T not available.

FreyJo · July 6, 2022, 9:32am

Hi,

I just tried adding this line:

acados_integrator.set("T", 0.1)

here:

github.com

acados/acados/blob/487224c52bcf6452af08236786b20fd56591245a/examples/acados_python/getting_started/sim/minimal_example_sim.py#L73

      
        
            sim.solver_options.newton_iter = 3 # for implicit integrator
            sim.solver_options.collocation_type = "GAUSS_RADAU_IIA"
            
            
# create
            acados_integrator = AcadosSimSolver(sim)
            
            
simX = np.ndarray((N+1, nx))
            x0 = np.array([0.0, np.pi+1, 0.0, 0.0])
            u0 = np.array([0.0])
            acados_integrator.set("u", u0)
            
            
simX[0,:] = x0
            
            
for i in range(N):
                # set initial state
                acados_integrator.set("x", simX[i,:])
                # initialize IRK
                if sim.solver_options.integrator_type == 'IRK':
                    acados_integrator.set("xdot", np.zeros((nx,)))
            
            
    # solve

and got the expected result, using the latest acados version.

jerluen · July 8, 2022, 7:34am

Hello,

I updated my repository and managed to resolve the issue.
However, I got a warning saying:

WARNING: acados Python interface could not close shared_lib handle of AcadosSimSolver POC_Integrator.
Attempting to create a new one with the same name will likely result in the old one being used!

Out of curiosity, what does this mean?
I attempted to create a new solver and it replaced to c generated code as intended.

Again, thank you very much for the help.

Jer Luen

FreyJo · July 26, 2022, 1:32pm

It means that the shared library is not unloaded successfully in Python.
Even when overwriting the generated code, there can still be binary stuff in the Python cache.

However, I fixed the destructor of AcadosSimSolver here: