**normal_ode**,
a Python code which
describes an ordinary differential equation (ODE)
for the normal probability density function (PDF).

The normal probability density function (PDF) can be written as

y(t) = 1/sqrt(2 pi) e^(-t^2/2)The derivative of the normal PDF is

y'(t) = -t/sqrt(2 pi) e^(-t^2/2) = - t * y(t)

Thus, along with an initial condition, an ODE for the normal PDF can be written either as:

y'(t) = -t/sqrt(2 pi) e^(-t^2/2)or

y'(t) = -t * y(t)While both of these ODE's have the same solution, an ODE solver will generally have more difficulty solving the second version.

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

**normal_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).

- normal_ode.py, the source code.
- normal_ode.sh, runs all the tests.
- normal_ode.txt, the output file.

- normal_ode.png, a plot of the solution using N and 2*N steps.
- normal_ode_error.png, a plot of the error using N and 2*N steps.