# Changes: 2.3.0

General:

- The equivalent of building BOPT=g, BOPT=O versions for PETSC_ARCH=linux-gnu is now: config/configure.py [options] -PETSC_ARCH=linux-gnu config/configure.py [options] –with-debugging=0 -PETSC_ARCH=linux-gnu-opt

- Python bindings added to PETSc. To use, configure with: –with-python=1 —with-shared=1 To build, use: ‘make python’ after building PETSc libraries. Example in src/snes/examples/tutorials/ex1.py

- Options database keys -trmalloc[_xxx] are changed to -malloc[_xxx]

- -get_resident_set_size and -trinfo are changed to -memory_info

- PetscTrValid() -> PetscMallocValidate(), PetscTrDebug() -> PetscMallocDebug()

- -trdebug -> -malloc_debug

- PetscGetResidentSetSize() -> PetscMemoryGetCurrentUsage(), added PetscMemoryGetMaximumUsage() and PetscMemorySetGetMaximumUsage()

- PetscTrSpace() -> PetscMallocGetCurrentUsage() and PetscMallocGetMaximumUsage()

- added PetscOptionsEnum() and PetscOptionsGetEnum()

- added PetscBag object for managing user created structs including initializing them and serializing them.

- removed PetscSetCommWorld(). Now you can directly assign to PETSC_COMM_WORLD before PetscInitialize().

Vec:

- Faster generation of VecScatter for many processes when indices are mostly sorted

- Changed BLAS-type interfaces to PETSc-style:

  - VecShift

  - VecScale

  - VecSet

  - VecSetRandom

  - VecAXPY

  - VecAXPBY

  - VecAYPX

  - VecMAXPY

  - VecWAXPY

- Changed order of arguments in pointwise routines:

  - VecPointwiseMult

  - VecPointwiseMax

  - VecPointwiseMin

  - VecPointwiseMaxAbs

  - VecPointwiseDivide

Mat:

- Changed MatConvert to require a reuse parameter to denote inplace converstion

- Added Cholesky and ICC support to SeqBAIJ

- Added the argument MatFactorInfo to MatLUFactorNumeric() and MatCholeskyFactorNumeric()

- Faster MatSetValues()

- Faster parallel-matrix vector products

- Changed MatCreate() to take only a communicator

- Added MatSetSize() to specify matrix sizes

- Changed BLAS-type interfaces to PETSc-style:

  - MatAXPY

  - MatAYPX

  - MatScale

  - MatShift

- Change MatZeroRows() and MatZeroRowsLocal() to use arrays, and added IS versions

PC:

- Added PCILUReorderForNonzeroDiagonal() and PCLUReorderForNonzeroDiagonal()

- Replace PCLUSetDamping(), PCILUSetDamping(), PCCholeskySetDamping() and PCICCSetDamping() by PCFactorSetShiftNonzero(). Change the option database keys -pc_lu_damping, -pc_ilu_damping, -pc_cholesky_damping and -pc_icc_damping to -pc_factor_shift_nonzero

- Replace PCLUSetShift(), PCILUSetShift(), PCCholeskySetShift() and PCICCSetShift() by PCFactorSetShiftPd(). Change the option database keys -pc_lu_shift, -pc_ilu_shift, -pc_cholesky_shift and -pc_icc_shift to -pc_factor_shfit_positive_definite

- PCMG: will automatically using the outer pmat operator to define the finest level operator if not user supplied

- PCMG: added MGUseGalerkin(), -pc_mg_galerkin option to have coarser grid matrices computed from the finest grid matrix

- PCMG: now does referencing counting on set vectors and restriction/interpolation matrices so user need not keep reference to free later

- PCMG: if user does not provide restriction the interpolation is used and vis versa

- PCMG: if user does not provide Vecs for each level, will automatically provide them

- All routines that began with MG now begin with PCMG

- Added PCShellSet/GetContext() and removed the context passed into PCSetApply() and PCSetApplyRichardson()

KSP:

- -ksp_cg_Hermitian and -ksp_cg_symmetric have been changed to -ksp_cg_type Hermitian or symmetric

- Changed options for -ksp_gmres_cgs_refinement_type from never or ifneeded or always to REFINE_NEVER or REFINE_IFNEEDED or REFINE_ALWAYS

config/configure.py:

SNES:

- Changed the name and calling sequence for SNESSetLineSearchCheck() to SNESLineSearchSetPostCheck() and added a SNESLineSearchSetPreCheck()

- Changed the names of all SNESxxxxLineSearchyyyy() to SNESLineSearchxxxxyyyy() per PETSc naming standard.

- Now allow a constant vector to be specified in SNESSolve()

- Removed the Vec argument from SNESSetUp()

- Corrected the order of function and context arguments in:

  - SNESGetFunction()

  - SNESGetJacobian()

TS:

DA:

- Added DAVecGet/RestoreArrayDOF() allowing indexing in the dimension of degrees of freedom at each point on the lattice.

- Faster DAGlobalToLocal() etc for dof > 1.

DMMG:

- Consolidated DMMG functionality into the new header file “petscdmmg.h”.

SYS:

- PetscSetCommWorld() removed. [one can directly do PETSC_COMM_WORLD = comm - before PetscInitialize()]

Fortran:

ExternalPackages:

- ML support added.