Elliptic 1D

Solves the 1D Poisson equation with Robin boundary conditions.

\[\nabla^2 u(x) = f(x)\]

with $x \in [0, 1]$ and $f(x) = e^x$. The boundary conditions are given by

\[a u + b \frac{du}{dx} = g\]

with $a = 1$, $b = 1$, and

\[a u(0) + b \frac{du(0)}{dx} = 0\]

\[a u(1) + b \frac{du(1)}{dx} = 2 e\]

This corresponds to the call to robinBC of robinBC(k, m, dx, a, b).

The true solution is

\[u(x) = e^x\]

This example is implemented in elliptic1D.jl