Issues Running Example "minimal_example_ocp.py" in python, Linux

User Questions
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1

I’m using the python interface and I’m attempting to run “python3 minimal_example_ocp.py” at the folder ~/acados/examples/acados_python/getting_started under a virtualenv environment set up as in the instructions here: Python Interface — acados documentation. I’m running Ubuntu 20.04.6 LTS on an 12th Gen Intel® Core™ i7-.

I’m getting 2 separate warnings/errors that I’m unsure if they’re related.

  1. Warning:
WARNING: Gauss-Newton Hessian approximation with EXTERNAL cost type not possible!
got cost_type: EXTERNAL, hessian_approx: 'GAUSS_NEWTON.'
GAUSS_NEWTON hessian is only supported for cost_types [NON]LINEAR_LS.
If you continue, acados will proceed computing the exact hessian for the cost term.
Note: There is also the option to use the external cost module with a numerical hessian approximation (see `ext_cost_num_hess`).
OR the option to provide a symbolic custom hessian approximation (see `cost_expr_ext_cost_custom_hess`).
  1. Error:
sh: 1: /home/factslabegmc/acados/bin/t_renderer: Permission denied
Traceback (most recent call last):
  File "minimal_example_ocp.py", line 104, in <module>
    main()
  File "minimal_example_ocp.py", line 83, in main
    ocp_solver = AcadosOcpSolver(ocp, json_file = 'acados_ocp.json')
  File "/home/factslabegmc/acados/interfaces/acados_template/acados_template/acados_ocp_solver.py", line 415, in __init__
    self.generate(acados_ocp, json_file=json_file, simulink_opts=simulink_opts, cmake_builder=cmake_builder)
  File "/home/factslabegmc/acados/interfaces/acados_template/acados_template/acados_ocp_solver.py", line 330, in generate
    ocp_render_templates(acados_ocp, json_file, cmake_builder=cmake_builder, simulink_opts=simulink_opts)
  File "/home/factslabegmc/acados/interfaces/acados_template/acados_template/acados_ocp_solver.py", line 123, in ocp_render_templates
    render_template(tup[0], tup[1], output_dir, json_path)
  File "/home/factslabegmc/acados/interfaces/acados_template/acados_template/utils.py", line 247, in render_template
    raise Exception(f'Rendering of {in_file} failed!\n\nAttempted to execute OS command:\n{os_cmd}\n\n')
Exception: Rendering of main.in.c failed!

Attempted to execute OS command:
/home/factslabegmc/acados/bin/t_renderer '/home/factslabegmc/acados/interfaces/acados_template/acados_template/c_templates_tera/**/*' 'main.in.c' '/home/factslabegmc/acados/examples/acados_python/getting_started/acados_ocp.json' 'main_pendulum_ode.c'

Any help would be much appreciated!

2

Hi,

this is your error, you should make this file executable:

3

I made the file executable with sudo chmod +x t_renderer
but the error message

sh: 1: /home/.../acados/bin/t_renderer: Permission denied

remains

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