Viscous Burgers' equation solved with a fractional step method.
The diffusion equation is solved in src1.f using Crank-Nicolson.
The tridiagonal system is solved using the LAPACK routine in tridiag.f.

The viscous coefficient eps is set in setprob.data.  

afterframe.m computes and plots the exact solution along with the computed
solution.  This is the exact solution to the Cauchy problem without a right
boundary.

Nonreflecting outflow boundary conditions are hard to specify for this
equation since a boundary condition at the right boundary is required for
this parabolic equation, and the solution depends on what is specified.
In src1.f, quadratic extrapolation is used and gives reasonable results, but
errors are apparent as the wave leaves the domain.