# Changes: 2.2.1#

General:

• Introduced 4 new PETSc data types: PetscInt, PetscErrorCode, PetscMPIInt and PetscBLASInt. For 99% of users these are just int or integer*4 and you do not need to change your code.

• For users with more than roughly 2 billion unknowns you can run configure with –with-64-bit-ints and then PetscInt will represent 64 bit integers, long long int in C and integer*8 in Fortran. But the the other 3 types remain 32 bit (i.e. int in C and integer*4 in Fortran). Now you can index into vectors and matrices with virtually unlimited sizes.

Vec:

• VecSetStashInitialSize() -> VecStashSetInitialSize()

• VecConvertMPIToAll() and VecConvertMPIToZero() have been replaced with VecScatterCreateToAll() and VecScatterCreateToZero()

IS:

• ISSum() now has a throughput argument instead of one in and one output.

Mat:

• MatSetStashInitialSize() -> MatStashSetInitialSize()

• added MatIsSymmetric(), MatIsTranspose() now take a tolerance flag for equality (use 0.0 for identical)

• added MatMPIAIJSetPreallocationCSR() and MatMPIBAIJSetPreallocationCSR()

PC:

• ICC now uses Manteuffel shift by default

• If matrix is symmetric, PC defaults to ICC when possible, if you told with MatSetOption(mat,MAT_SYMMETRIC)

• PCSetVector() is gone (no longer needed)

• PCNullSpaceAttach() is gone, use KSPSetNullSpace()

• MatGetSubmatrices() now preserves symmetric flag of original matrix

• hypre BoomerAMG (-pc_type hypre -pc_hypre_type boomeramg) now uses one 1 cycle of multigrid as preconditioner (Previously it used either a decrease in residual of 10^-7 or a maximum of 20 iterations

KSP:

• Note that a relative residual tolerance now means that ||r_k|| < tol*||b||

• Removed KSPSetRhs() and KSPSetSolution(), pass

• Added KSPSetNullSpace(), KSPGetNullSpace()

DA:

• Added DAGetGhostedCoordinates() and DAGetCoordinateDA() (see src/dm/da/examples/tutorials/ex3.c)

• Added DACoor2d and DACoor3d (see src/dm/da/examples/tutorials/ex3.c)

• DAGetInterpolation() now provides the correct interpolation for nonuniform grids using the coordinate information provided with DASetCoordinates(). (see src/dm/da/examples/tutorials/ex3.c)

config/configure.py:

• added configure support (without download) to Mumps, UMF, Superlu,SuperLU_dist,DSCPACK

• Made configure much more robust

SNES:

• Added SNESSetRhs(snes,rhs) to allow for solving F(x) = rhs

TS:

DMMG: