petsc-3.7.1 2016-05-15
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# Documentation: Changes: 2.0.28

## CHANGES in PETSc 2.0.28 (see new features)

#### General:

- No longer support PETSC_ARCH=sun4
- The macros in petscconf.h now begin with PETSC_
- `PetsReal()` and `PetscImaginary()` are now `PetscRealPart()` `PetscImaginaryPart()`
- -optionstable -> -options_table -optionsleft -> -options_left but old left for compatibility

#### AO (Application Orderings):

#### TS (Timestepping Solvers):

- `TSSetMonitor()` now takes an additional final optional argument that monitor context.

#### SNES (Nonlinear Solvers):

- SNES_EQ_LS etc changed to drop _, for example SNESEQLS
- Changed calling sequence of SNES monitoring routines to add an additional output parameter indicating why it converged or diverged.
- Added additional final argument to `SNESSetMonitor()` an optional destroy routine for the monitor context.
- Changed calling sequence of `MatSNESMFAddNullSpace()` to take `PCNullSpace` object rather than array of vectors.
- Added final ctx argument to `SNESGetFunction()`, `SNESGetGradient()` and `SNESGetMinimizationFunction()`

#### SLES (Linear Solvers):

- See PC and KSP
- `SLESSolveTrans()` is now `SLESSolveTranspose()`
- `SLESSolve()` now ALWAYS returns a 0 or positive iteration count. Call `KSPGetConvergedReason()` to see if converged or diverged and why.

#### KSP (Krylov Subspace Methods):

- Added additional final argument to `KSPSetMonitor()` an optional destroy routine for the monitor context.
- `KSPSolvetrans()` is now `KSPSolveTranspose()`
- Added flexible gmres (use fgmres or KSPFGMRES as the type) see `KSPFGMRESSetModifyPC()` for one way to change PC at each iteration.

#### PC (Preconditioners):

- `MGSetRestriction()` and `MGSetInterpolation()` now accept PETSc figures out which one it is based on the number of rows and columns. Now you don't need to use the Shell matrices if you computed it "the other way then PETSc use to expect".
- `PCApplyTrans()` is now `PCApplyTranspose()`
- options -pc_ilu_mat_ordering_type <nd,...> and -pc_lu_mat_ordering_type <nd,...> now set the ordering type.

#### MAT (Matrices):

- Added two additional arguments to `MatCreate(MPI_Comm comm,int m,int n,int M,int N,Mat *)` where m and n are the local ownership sizes. To get the effect of the old `MatCreate()` use m and n equal to PETSC_DECIDE
- Changed `MatSetLocalToGlobalMappingBlocked()` to `MatSetLocalToGlobalMappingBlock()` so that it would be less then 32 characters long.
- `MatSolveTrans()`and `MatSolveTransAdd()` are now `MatSolveTransposeXXX()` `MatMultTrans()` and `MatMultTransAdd()`are now `MatMultTransposeXXX()`
- `MatCreateMPIAdj()` changed to `MatCreateMPICSR()`; `MatCreateSeqAdj()` dropped.
- Another `MatSetOption()`, `MAT_IGNORE_ZERO_ENTRIES` for AIJ matrices with `ADD_VALUES`.
- added matrix option `MAT_KEEP_ZEROED_ROWS` causes `MatZeroRows()` to keep the original nonzero data structure and just put 0.0 into the elements that are to be zeroed. Without this option it removes the locations from the nonzero structure.

#### DA (Distributed Arrays):

#### VEC (Vectors):

- Added VecGetArray2d() and VecRestoreArray2d()

#### IS (Index Sets):

- Added second argument to `ISInvertPermutation`() that indicates how many indices are to be stored on that processor; ignored for one processor code. If you use `ISInvertPermutation`() simply add a second argument of `PETSC_DECIDE`.

#### Draw (Graphics):

- DrawHistxxx changed to DrawHGxxx

#### Viewers:

#### System:

- Routines XXXRegister() are now XXXRegisterDynamic() used for registering new object types in dynamic libraries and XXXRegister_Private() is now XXXRegister() used to register new object types whose definitions are in the exectuable.
- The final argument to OptionsHasName() and OptionsGetXXX() is a PetscTruth * instead of an int*
- PETSc functions and objects that began with Table now begin with PetscTable
- Changed these routines to return an error code. extern int PetscStrchr(const char[],char,char **); extern int PetscStrrchr(const char[],char,char **); extern int PetscStrstr(const char[],const char[],char **); extern int PetscStrtok(const char[],const char[],char **); extern int PetscStrlen(const char[],int *); added PetscStrallocpy(const char[],char **); PetscStrncmp() and PetscStrcasecmp() now return PETSC_TRUE as a final argument if the strings match else PETSC_FALSE. Note this means removing ! from your current tests and adding it where you don't have it.
- PetscMemcmp() now has a final argument of true for matching memories.
- The Fortran versions of the PetscStrxxx() and PetscMemxxx() routines also now have the error flag as the final argument
- PetscFree() now always returns an error code that may be checked with CHKERRQ(). On systems where free() returns a void (and the user has no access to an error condition in free(), PetscFree() returns 0 i.e. no error; on other systems it returns the error number from free.
- The BT bitarray macros are now prefixed with PetscBT

#### Error Handling:

#### Event Logging:

#### Fortran Interface:

## New features in PETSc 2.0.28 (see changes above)

#### General:

- When doing string substitutions in library directory paths etc one must use ${PETSC_DIR} ${BOPT} etc now instead of $PETSC_DIR etc. Also you can put anything in {anything} as long as it is an environmental variable or passed in the options database with -anything
- Added PetscEmacsclientErrorHandler() -on_error_emacs [machinename] to allow emacs to jump to error; can be used with any other error handler.
- So long as you have defined the macro __FUNC__ "main" before your main C/C++ subroutine you can use SETERRQ() and CHKERRQ() instead of SETERRA(), CHKERRA().

#### AO (Application Orderings):

#### TS (Timestepping Solvers):

#### SNES (Nonlinear Solvers):

- Added `SNESSetLineSearchParams()` and `SNESGetLineSearchParams()`, contributed by Matt Knepley.
- Added `SNESGetConvergedReason()` to find out if a `SNESSolve()` has converged/diverged and why
- Added `SNESMonitorVecUpdate()` and -snes_vecmonitor_update to display the Newton update at each iteration.

#### SLES (Linear Solvers):

- See PC and KSP

#### KSP (Krylov Subspace Methods):

- Added -ksp_gmres_krylov_monitor and `KSPGMRESKrylovMonitor()` to allow one to view the vectors in the Krylov space.

#### PC (Preconditioners):

- We now provide a drop tolerance based ILU for SeqAIJ matrix format via Yousef Saad's SPARSEKIT2 software. Use -pc_ilu_use_drop_tolerance <dt,dtcol,rowmax> or `PCILUSetUseDropTolerance`(pc,dt,dtcol,rowmax).

#### MAT (Matrices):

#### DA (Distributed Arrays):

#### VEC (Vectors):

#### IS (Index Sets):

#### Draw (Graphics):

- `DrawCreate()` and `DrawOpenX()` now can take

#### Viewers:

- Added `ViewerASCIIUseTabs()` to allow turning off tabbing during certain viewer operations.
- Added `ViewerGetSingleton()`, ViewerRestoreSingleton() to allow managing the calling a a sequential viewer from within a parallel viewer.
- Added `ViewerASCIISynchronizedPrintf`(viewer,....)
- Binary and ASCII viewers can create compressed files by simply appending a .gz on the filename.
- PETSc now has a new viewer that generates rudimentary Postscript. Improvements, additions may be added as needed. `DrawOpenPS()`, or `DrawSetType(,DRAW_PS);` or -draw_type ps

#### System:

- using -trdump with PETSC_USE_STACK compile option (default for BOPT=g*) will print the entire stack for each malloc, allow one to more easily track down where mallocs where made that where not freed.
- Added PetscSum_Op to replace MPI_SUM for reductions with MPIU_SCALAR
- Added PetscMaxSum_Op to do max on first half of entries and sum on second half.
- Added CHKMEMQ and CHKMEMA macros to help track down memory corruption.

#### Error Handling:

#### Event Logging:

#### Fortran Interface:

- Added Fortran 90 interface support for HP Convex and Solaris.machine.