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<li class="toctree-l2"><a class="reference external" href="https://web.cels.anl.gov/projects/petsc/vault/petsc-3.22/docs"> 3.22</a></li>
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<li class="toctree-l2"><a class="reference external" href="https://web.cels.anl.gov/projects/petsc/vault/petsc-3.15/docs"> 3.15</a></li>
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<section class="tex2jax_ignore mathjax_ignore" id="changes-3-3">
<h1>Changes: 3.3<a class="headerlink" href="#changes-3-3" title="Link to this heading">#</a></h1>
<p class="rubric">config/configure.py:</p>
<ul class="simple">
<li><p>Building PETSc using CMake is enabled automatically if CMake is
installed (enabling parallel builds and fast incremental builds),
otherwise the plain make-based system is used.</p></li>
<li><p>Added –with-cuda-only flag to allow compiling CUDA files without
requiring Thrust and Cusp</p></li>
</ul>
<p class="rubric">Vec:</p>
<ul class="simple">
<li><p>VecCreateSeqWithArray() and VecCreateMPIWithArray() now take a
blocksize argument before the local length</p></li>
<li><p>VecSetBlockSize() cannot be called after VecCreateSeq() or
VecCreateMPI() and must be called before VecSetUp() or
VecSetFromOptions() or before either VecSetType() or VecSetSizes()</p></li>
</ul>
<p class="rubric">Mat:</p>
<ul class="simple">
<li><p>MatScaleSystem() and MatUnScaleSystem() are gone, they didn’t do
anything.</p></li>
<li><p>Renamed MatNullSpaceAttach() to MatSetNullSpace()</p></li>
<li><p>MatMult() no longer removes the nullspace set by MatSetNullSpace()</p></li>
<li><p>Renamed MatMatMultTranspose() for C=A^T*B to MatTransposeMatMult()</p></li>
<li><p>Added MatMatTransposeMult() for C=A*B^T</p></li>
<li><p>Added MatRARt() for C=R*A*R^T</p></li>
<li><p>Preallocation routines now automatically set
MAT_NEW_NONZERO_ALLOCATION_ERR, if you intentionally preallocate
less than necessary then use
MatSetOption(mat,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE) to
disable the error generation.</p></li>
<li><p>MatSetBlockSize() must be called before MatSetUp() or
MatXXXXSetPreallocation() or block size defaults to 1</p></li>
<li><p>-mat_block_size is NOT processed by MatXXXXSetPreallocation() you
MUST call MatSetFromOptions() before MatSetUp() to have it
processed</p></li>
<li><p>You MUST now call MatXXXSetPreallocation() or MatSetUp() on any
matrix you create directly (not using DMCreateMatrix()) before
calling MatSetValues(), MatSetValuesBlocked() etc.</p></li>
<li><p>MatGetOwnershipRange() will not work without setting up the
matrix.</p></li>
<li><p>MatSetUpPreallocation() and MatPreallocated() are removed, use
MatSetUp()</p></li>
<li><p>MatPreallocateSymmetricInitialize() is removed, use
MatPreallocateInitialize()</p></li>
<li><p>MatCreateMPIAIJ(), MatCreateMPIBAIJ(), MatCreateMPISBAIJ(),
MatCreateMPIDense() are now MatCreateAIJ(), MatCreateBAIJ(),
MatCreateSBAIJ(), MatCreateDense(). Note that on a single process
they have always created the sequential version of the matrix so
this naming is more accurate.</p></li>
<li><p>Renamed MatMerge_SeqsToMPI() to MatCreateMPIAIJSumSeqAIJ()</p></li>
<li><p>Renamed MatMerge() to MatCreateMPIAIJConcatenateSeqAIJ()</p></li>
<li><p>Added block size in call to MatCreateIS()</p></li>
<li><p>MatInvertBlockDiagonal() now returns a const pointer</p></li>
</ul>
<p class="rubric">PC:</p>
<ul>
<li><p>Remove PCASASetDM(), use PCSetDM() instead.</p></li>
<li><p>Add PCFieldSplitSetSchurFactType(), rename
-pc_fieldsplit_schur_factorization_type to
-pc_fieldsplit_schur_fact_type.</p></li>
<li><p>Added native algebraic multigrid method -pc_type gamg. Aggregation
method is recommended: -pc_gamg_type agg and for elliptic
operators smoothing is recommended: -pc_gamg_agg_nsmooths 1.</p></li>
<li><p>PCSetCoordinates(PC,PetscInt,PetscInt,PetscReal*) added second
integer argument for number of local vertices.</p></li>
<li><p>Added PCISSetSubdomainScalingFactor(PC,PetscScalar).</p></li>
<li><p class="rubric">PCGASM:</p>
<ul class="simple">
<li><p>Remove PCGASMSetLocalSubdomains(), use PCGASMSetSubdomains();
<strong>note:</strong> the first argument is now the list of “inner”
subdomains (without overlap), unlike before and for PCASM</p></li>
<li><p>PCGASMSetTotalSubdomains(PC,PetscInt,PetscBool); added third
argument to indicate whether local subdomains should be
constructed.</p></li>
<li><p>Removed PCGASMCreateSubdomains(), use
PCGASMCreateLocalSubdomains(Mat,PetscInt,PetscInt,IS*[],IS*[]);
second PetscInt argument is requested overlap</p></li>
<li><p>PCGASMCreateSubdomains2D(PC,PetscInt,PetscInt,PetscInt,PetscInt,PetscInt,PetscInt,PetscInt*,IS[]*,IS[]*):
the 9-th and 10-th argument have been swapped: the 9-th outputs
the inner subdomains, the 10-th outputs the outer subdomains.</p></li>
</ul>
</li>
<li><p>PCMG multigrid defaults changed to use a Chebyshev smoother with
block Jacobi Gauss-Seidel relaxation. This is a linear
preconditioner so it can be used with normal Krylov methods rather
than only flexible methods, as well as having fewer
synchronization pointst. Use
<code class="docutils notranslate"><span class="pre">-mg_levels_ksp_type</span> <span class="pre">gmres</span> <span class="pre">-mg_levels_ksp_max_it</span> <span class="pre">1</span> <span class="pre">-mg_levels_pc_type</span> <span class="pre">bjacobi</span></code>
for the original behavior.</p></li>
</ul>
<p class="rubric">KSP:</p>
<ul class="simple">
<li><p>KSPSetOperators() will automatically set the null space present on
the input matrix</p></li>
<li><p>Renamed KSPCHEBYCHEV to KSPCHEBYSHEV</p></li>
<li><p>Added Hybrid CHEBYCHEV (-ksp_chebyshev_hybrid)</p></li>
<li><p>Added pipelined GMRES (KSPPGMRES) which performs one non-blocking
reduction per iteration instead of two blocking reductions.</p></li>
<li><p>Added flexible BiCGStab (KSPFBCGS) which tolerates a nonlinear
preconditioner (like KSPFGMRES).</p></li>
<li><p>Added improved flexible BiCGStab (KSPIFBCGS) which tolerates a
nonlinear preconditioner and performs one reduction every other
iteration (like KSPIBCGS).</p></li>
</ul>
<p class="rubric">SNES:</p>
<ul class="simple">
<li><p>Added SNESGetSNESLineSearch</p></li>
<li><p>Changed default max_its and max_funcs for non-newton SNES solvers
to 10000 and 30000 respectively</p></li>
<li><p>Changed options and command-line arguments for SNESFAS to be in
line with PCMG</p></li>
<li><p>Added quasi-Newton (SNESQN), Nonlinear GMRES (SNESNGMRES),
nonlinear conjugate gradients (SNESNCG), and multi-stage methods
(SNESMS, used as a smoother for nonlinear multigrid).</p></li>
<li><p>Support for Full Approximation Scheme nonlinear multigrid
(SNESFAS) moved from DMMG to SNES and made composable with the
methods above.</p></li>
<li><p>SNES line search type should be set by name with
SNESLineSearchSetType rather than with SNESLineSearchSet, see
below.</p></li>
</ul>
<p class="rubric">SNESLineSearch:</p>
<ul class="simple">
<li><p>SNESLineSearch object added</p></li>
<li><p>The default SNESLineSearch of a SNES may be gotten with
SNESGetSNESLineSearch(SNES snes, SNESLineSearch *linesearch)</p></li>
<li><p>The linesearch type may be set with SNESLineSearchSetType() or
-snes_linesearch_type</p></li>
<li><p>The line search (and pre and post checks) is applied using
SNESLineSearchApply()</p></li>
<li><p>Pre/Post-check methods may be set with
SNESLineSearchSetPre/PostCheck()</p></li>
<li><p>The previous steplength may be accessed through
SNESLineSearchSetLambda()</p></li>
<li><p>The damping parameter may be set through
SNESLineSearchSetDamping() or -snes_linesearch_damping</p></li>
<li><p>Success of the line search is determined using
SNESLineSearchGetSuccess()</p></li>
<li><p>Custom linesearches may be built through
SNESLINESEARCHSHELL,(“shell”) or by registering a new linesearch
type with SNESLineSearchRegisterDynamic()</p></li>
<li><p>SNESLINESEARCHBT,(“bt”) replaces SNES_LS_CUBIC and
SNES_LS_QUADRATIC, and order may be set with
SNESLineSearchSetOrder() or -snes_linesearch_order</p></li>
<li><p>SNESLINESEARCHBASIC,(“basic”) replaces SNES_LS_BASIC and
SNES_LS_BASICNONORMS. Norms may be turned off with
SNESLineSearchSetComputeNorms() or -snes_linesearch_norms 0</p></li>
<li><p>SNESLineSearchSetTolerances() replaces SNESLSSetParams(), with the
former alpha parameter set with SNESLineSearchBTSetAlpha() or
-snes_linesearch_alpha</p></li>
<li><p>Added Line Search type SNESLINESEARCHL2,(“l2”) as the default for
NRICHARDSON</p></li>
<li><p>SNESLINESEARCHCP,(“cp”) added as the default line search method
for SNESNCG and SNESQN</p></li>
</ul>
<p class="rubric">TS:</p>
<ul class="simple">
<li><p>-ts_max_time changed to -ts_final_time</p></li>
<li><p>TSDefaultComputeJacobian() and TSDefaultComputeJacobianColor()
have been removed. Configure TS to use coloring with
SNESSetJacobian().</p></li>
<li><p>Added TSROSW for Rosenbrock-W methods.</p></li>
<li><p>Added a common, extensible system for adaptive controllers, see
TSGetAdapt().</p></li>
</ul>
<p class="rubric">DM/DA:</p>
<ul class="simple">
<li><p>Added DMCreateDecomposition(DM,PetscInt,char*[]*,IS[]*,DM[]*) for
use with PCFIELDSPLIT,PCASM,PCGASM</p></li>
<li><p>Added DMCreateDecompositionDM(DM,const char*,DM*) to create a
version of the DM encapsulating a named decomposition; use with
DMCreateDecomposition()</p></li>
<li><p>Added DMRedundant for managing globally coupled degrees of
freedom.</p></li>
<li><p>Removed DMCompositeAddArray(), use DMRedundantCreate() and
DMCompositeAddDM().</p></li>
<li><p>Renamed DMGetMatrix(), DMGetInterpolation(), DMGetInjection(), and
DMGetColoring() to DMCreateMatrix(), etc for semantic consistency.</p></li>
<li><p>The communicator argument to DMRefine() and DMCoarsen() can be
MPI_COMM_NULL, but not PETSC_NULL, because the latter may not be
the correct type.</p></li>
<li><p>Added DMCoarsenHookAdd() and DMRefineHookAdd() for shepherding
persistent resolution-dependent data between levels.</p></li>
<li><p>Added DMGetNamedGlobalVector() for storing persistent
resolution-dependent data.</p></li>
<li><p>DMDASNESSetFunctionLocal() and DMDASNESSetJacobianLocal() can be
used for convenient local evaluation; these routines will
eventually replace DMDASetLocalFunction() and
DMDASetLocalJacobian().</p></li>
</ul>
<p class="rubric">DMMG:</p>
<ul class="simple">
<li><p>DMMG is now completely removed from PETSc. Equivalent (and better)
functionality can now be obtained by calling SNESSetDM() or
KSPSetDM(). Make sure to avoid resolution-dependent data in the
user context. Use SNESGetDM() or KSPGetDM() in the function
evaluation context to obtain the grid. DMGetNamedGlobalVector(),
DMCoarsenHookAdd(), and DMRefineHookAdd() can be used to manage
persistent resolution-dependent data.</p></li>
</ul>
<p class="rubric">PetscViewer:</p>
<ul class="simple">
<li><p>A VTK binary viewer was added, see PETSCVIEWERVTK.</p></li>
</ul>
<p class="rubric">SYS:</p>
<ul class="simple">
<li><p>PetscBagLoad() now requires you previously created and registered
all the records in the PETSc bag, allows loading on systems with
different struct layout/endianness.</p></li>
<li><p>PetscSF added as a type-generic graph communication mechanism. The
current implementation requires MPI-2 one-sided and the interface
is currently optional.</p></li>
</ul>
<p class="rubric">Fortran:</p>
<ul class="simple">
<li><p>PETSC_NULL_TRUTH is now PETSC_NULL_BOOL</p></li>
<li><p>PetscOptionsGetEnum() now available from Fortran</p></li>
</ul>
<p class="rubric">ExternalPackages:</p>
<ul class="simple">
<li><p>The Hypre interface was updated to 2.8.0b and now supports 64-bit
integers.</p></li>
<li><p>SuperLU_DIST interface updated to 3.1.</p></li>
<li><p>SuperLU interface updated to 4.3.</p></li>
<li><p>Sundials interface updated to 2.5.0.</p></li>
<li><p>FFTW interface updated to 3.3.2.</p></li>
<li><p>ParMetis updated to 4.0.2 and split from Metis 5.0.2 which is now
separate.</p></li>
</ul>
<p class="rubric">Build:</p>
<ul class="simple">
<li><p>If Python 2.7 is available, the config/builder2.py is now
available for a complete build, including dependency tracking.</p></li>
</ul>
<p class="rubric">Examples:</p>
<ul class="simple">
<li><p>SNES ex62 illustrates the use of DMComplex to solve the Stokes
equation on an unstructured mesh. The Python tests show how to use
block preconditioning strategies from the command line.</p></li>
<li><p>SNES ex52 illustrates the use of CUDA for FEM integration</p></li>
</ul>
</section>
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