Solve Burgers' equation with data:

q(x,0) = q1 for x < 0
         q2 for x > 0

with periodic boundary conditions. The true solution coded in setplot.py assumes that q1 < q2 so there is a shock coming in from the left boundary while the discontinuity at the origin gives a rarefaction wave. q1 and q2 can be changed in setrun.py

The parameter efix can be set in setrun.py to specify whether the entropy fix is used in the Riemann solver rp1_burgers.f90.

Note how these parameters are read in by setprob.f90 and passed to the routines where they are needed via common blocks.