== !PyLith Development Plans ==
 Software development plans for !PyLith
=== Version 1.6 (by June training session) ===
==== OPTIMIZATION ====
  * Multiple fields in a single Sieve section done[[br]]
     At this point, only used for parameters of fault constitutive models.

==== GENERAL ====
  * HDF5 output done [[br]]
     Output into a single HDF5 file or an HDF5 file with raw binary files for the datasets. Datasets are written using MPI I/O if available in both cases. Add !.Xdmf metadata files associated with HDF5 files to permit reading of HDF5 files with !ParaView and Visit.

  * Uniform global refinement done (98%)
==== QUASI-STATIC ====
  * Added 2-D plane strain versions of the 3-D generalized Maxwell viscoelastic rheology. done
==== DYNAMIC ====
  * Numerical damping via viscosity done[[br]]
     Added numerical damping via a viscosity parameter that is independent of the bulk constitutive model. The viscosity is applied during the time integration.

==== COMPUTATIONAL SCIENCE ====
  * None
=== Version 1.7 (Fall 2011) ===
==== OPTIMIZATION ====
  * Multiple fields in a single Sieve section intermediate (0%)
     * Parameters for bulk constitutive models
     * Parameters and fields related to fault implementation[[br]]

     Will reduce memory use and provide speedup due to better use of memory cache.

==== CLEANUP ====
  * Separate elastic solution into elasticPrestep() function easy (0%)
  * Add --initialize_only property to Problem easy (0%) [[br]]
     Permit users to stop simulation before time stepping in order to diagnose parameter settings.

==== GENERAL ====
  * Refactor initial fault tractions easy (5%) [[br]]
     Create Nucleation object with spatial and temporal perturbation of tractions from initial value

==== QUASI-STATIC ====
  * Add strain hardening/softening to Drucker-Prager elastoplastic models.
==== DYNAMIC ====
  * Compute stable time step for explicit time integration easy (5%)
  * Attenuation via generalized Maxwell model (bulk and shear relaxation) intermediate (50%)
==== COMPUTATIONAL SCIENCE ====
  * Scalable mesh distribution intermediate (0%) [[br]]
     Permit running large problems where the mesh cannot fit on a single compute node.

  * Accelerate FE integrations using GPUs difficult (25%) [[br]]
     Will provide significant speedup to simulations run by many users because most are running on desktop machines that have GPUs.

=== Version 2.0 ===
==== OPTIMIZATION ====
  * TBD
==== CLEANUP ====
  * TBD
==== GENERAL ====
  * Moment tensor point sources[[br]]
     Moment tensor point sources provide a mesh independent deformation source that is better suited for Green's function calculations than slip on a fault surface via cohesive cells. difficult

==== QUASI-STATIC ====
  * Time-step based on strain rate intermediate
  * Pressure field for incompressible elasticity problems expert
==== DYNAMIC ====
  * TBD
==== COMPUTATIONAL SCIENCE ====
  * Use KD tree search algorithm to allow output of time histories at an arbitrary location difficult
  * Use interpolated meshes (cells, faces, edges, vertices) to permit higher order basis functions expert
  * Support for arbitrary number of solution fields (e.g., displacement, temperature, pressure) expert
  * Adjust integrations to support multi-physics calculations.
=== Beyond Version 2.0 ===
==== OPTIMIZATION ====
  * TBD
==== CLEANUP ====
  * TBD
==== GENERAL ====
  * Combined prescribed slip / spontaneous rupture fault condition[[br]]
     Use fault constitutive model to control slip on fault except during episodes of prescribed slip. Need some way to describe when to turn on/off prescribed slip.

==== QUASI-STATIC ====
  * TBD
==== DYNAMIC ====
  * TBD
==== COMPUTATIONAL SCIENCE  ====
  * TBD