pendulum_elastic_ode

pendulum_elastic_ode, a Python code which sets up and solves the ordinary differential equations (ODE) that represent the behavior of a nonlinear elastic pendulum, with gravitational force G, spring constant K, unstretched length L, and mass M.

Licensing:

The computer code and data files described and made available on this web page are distributed under the MIT license

Languages:

pendulum_elastic_ode is available in a MATLAB version and an Octave version and a Python version.

Related Data and codes:

pendulum_elastic_ode_test

python_ode, Python codes which sets up various systems of ordinary differential equations (ODE).

Reference:

• Paul D Williams,
  The RAW Filter: An Improvement to the Robert–Asselin Filter in Semi-Implicit Integrations,
  Monthly Weather Review,
  Volume 139, pages 1996-2007, June 2011.

Source Code:

• pendulum_elastic_ode.py, calls all the tests.
• pendulum_elastic_ode.sh, runs all the tests.
• pendulum_elastic_ode.txt, the output file.

• pendulum_elastic_solve_ivp_energy.png, a plot of the energy of the nonlinear pendulum behavior over time.
• pendulum_elastic_solve_ivp_theta.png, a plot of the angular deflection over time.
• pendulum_elastic_solve_ivp_theta_phase.png, the theta phase plot.
• pendulum_elastic_solve_ivp_nu.png, a plot of the strain over time.
• pendulum_elastic_solve_ivp_nu_phase.png, the theta phase plot.