i><a href="https://www.mcs.anl.gov/petsc/petsc-current/src/snes/tutorials/ex19.c.html#line246">physics source code</a></li>
</ul>

<p>DO THE FOLLOWING:</p>
<ul>
  <li> Compile src/snes/tutorials/ex19.c
    <pre>
      cd petsc/src/snes/tutorials/
      make ex19
  </pre>
  </li>
  <li> Run a 4 processor example with 5 levels of grid refinement, monitor the convergence of the nonlinear and linear solver
      and examine the exact solver used
    <pre>
     mpiexec -n 4 ./ex19 -da_refine 5 -snes_monitor -ksp