**sling_ode**,
a Python code which
sets up and solves a system of ordinary differential equations
(ODE) for which the exact circular solution can only be approximated
for a short interval before it spirals to the origin.

A parameter S has the default value 1, and corresponds to rapid decay of the solution. If S is decreased towards 0, the computed solution is better able to stay close to the exact circular path. Once S becomes negative, however, the approximated solutions will tend to spiral out to infinity.

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

**sling_ode** is available in
a MATLAB version and
an Octave version and
a Python version.

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

- sling_ode.m, the source code.
- sling_ode.sh, runs all the tests.
- sling_ode.txt, the output file.

- sling_solve_ivp_plot_1.png, a plot of two solution components over time, for s = 1.
- sling_solve_ivp_phase_1.png, a phase plot, for s = 1.
- sling_solve_ivp_conservation_1.png, a plot of the energy over time, for s = 1.
- sling_solve_ivp_plot_0.4.png, a plot of two solution components over time, for s = 0.4.
- sling_solve_ivp_phase_0.4.png, a phase plot, for s = 0.4.
- sling_solve_ivp_conservation_0.4.png, a plot of the energy over time, for s = 0.4.