* time-dependent simulation. It manages stepping forward from a start time
* $T_{\text{start}}$ to an end time $T_{\text{end}}$. It also allows adjusting
* the time step size during the simulation. This class provides the necessary
- * interface to be incorporated in any time-dependent simulation. As an
- * example, the usage of this class is demonstrated in step-21. This class
- * attempts to replace the usage of TimestepControl with a better and more
- * modern interface.
+ * interface to be incorporated in any time-dependent simulation.
+ * The usage of this class is demonstrated in step-19 and step-21.
*
* This class provides a number of invariants that are guaranteed to be
* true at all times.
* // } end snapshot stage
* }
* @endcode
+ * The `run()` function in step-19 shows a very similar example where the call
+ * to advance_time() ends the update stage and is followed by generating
+ * graphical output with the then-current time.
*/
class DiscreteTime
{
* the geometry of the domain, and in this case ignoring the exception is
* probably unwise.
*
- * @note This function is used in step-14 .
+ * @note This function is used in step-14 and step-19.
*
- * @note This function triggers the create signal after doing its work. See
+ * @note This function triggers the "create" signal after doing its work. See
* the section on signals in the general documentation of this class.
*
* @note The check for distorted cells is only done if dim==spacedim, as
* <h3> An example </h3>
*
* A common example of what one wants to do with postprocessors is to visualize
- * not just the value of the solution, but the gradient. Let's, for simplicity,
+ * not just the value of the solution, but the gradient. This is, in fact,
+ * precisely what step-19 needs, and it consequently uses the code below almost
+ * verbatim. Let's, for simplicity,
* assume that you have only a scalar solution. In fact, because it's readily
* available, let us simply take the step-6 solver to produce such a scalar
* solution. The gradient is a vector (with exactly @p dim components), so the
*
* The connected function receives an iterator to the particle in
* question, and its last known cell association.
+ *
+ * This signal is used in step-19.
*/
boost::signals2::signal<void(
const typename Particles::ParticleIterator<dim, spacedim> &particle,