M1 Mathematics, 2011-2012
MM26E Numerical Approximation of PDEs

Hervé Le Dret

The finite difference method for the heat equation

The backward Euler method

Below is an animation showing a computation of the heat equation solution using the implicit Euler method, thus unconditionally stable. Here we have $\frac{k}{h^2}=200$. The initial data does not satisfy the homogeneous Dirichlet condition (it is equal to $1$ on $[0,1]$). The exact solution is thus not regular at $t=0$. This does not prevent the method from converging quite well.



The animation is cut well before $t=1$, since nothing spectacular happens, then loops back at $t=0$. Computations performed with Scilab.