**tough_ode_test**,
an Octave code which
calls tough_ode(), which
sets up a system of four ordinary differential equations (ODE).

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

tough_ode, an Octave code which sets up a system of four ordinary differential equations (ODE).

- tough_ode_test.m, calls all the tests.
- tough_ode_test.sh, runs all the tests.
- tough_ode_test.txt, the output file.

- midpoint.m, a version of the implicit midpoint ODE solver.
- tough_midpoint.m, uses midpoint() to solve the problem.
- tough_midpoint_y1.png, a plot of y1 over time.
- tough_midpoint_y2.png, a plot of y2 over time.
- tough_midpoint_y3.png, a plot of y3 over time.
- tough_midpoint_y4.png, a plot of y4 over time.

- tough_ode23.m, uses ode23() to solve the problem.
- tough_ode23_y1.png, a plot of y1 over time.
- tough_ode23_y2.png, a plot of y2 over time.
- tough_ode23_y3.png, a plot of y3 over time.
- tough_ode23_y4.png, a plot of y4 over time.

- tough_ode45.m, uses ode45() to solve the problem.
- tough_ode45_y1.png, a plot of y1 over time.
- tough_ode45_y2.png, a plot of y2 over time.
- tough_ode45_y3.png, a plot of y3 over time.
- tough_ode45_y4.png, a plot of y4 over time.