# Changes: 2.0.16

```{rubric} General:
```

- Added the option -compare option for incremental debugging; see
  the users manual for more details.
- Added tags file so that vi users can easily browse PETSc source
  files (just as emacs users already can by using etags). See the
  users manual subsection "VI users" for details.
- We have stopped distributing the Unix-style manpages with PETSc.
  Instead, we now only distribute the HTML version. You can still
  access the man pages with the command \$PETSC_DIR/bin/petscman.
  Alternatively, you can directly view \$PETSC_DIR/docs/www/www.html.

```{rubric} TS (Timestepping Solvers):
```

```{rubric} SNES (Nonlinear Solvers):
```

- You can now attach several SNES monitoring routines with
  SNESMonitorSet() instead of only one as previously allowed.
  Similarly, multiple monitors can be used from the options database
  (e.g., -snes_monitor and -snes_xmonitor).

```{rubric} SLES (Linear Solvers):
```

- See PC and KSP

```{rubric} KSP (Krylov Subspace Methods):
```

- You can now attach several KSP monitoring routines with
  KSPSetMonitor() instead of only one as previously allowed.
  Similarly, multiple monitors can be used from the options database
  (e.g., -ksp_monitor and -ksp_xmonitor).

```{rubric} PC (Preconditioners):
```

```{rubric} MAT (Matrices):
```

- Added the routines MatSetValuesLocal(), MatZeroRowsLocal() and
  MatSetLocalToGlobalMapping() to enable the user to set values in a
  matrix using a local numbering of the nodes rather than a global
  numbering.
- Added the option MAT_IGNORE_OFF_PROC_ENTRIES for MatSetOption(),
  which causes all entries on any processor destined to be stored on
  a different processor to be dropped instead. This is useful if you
  know that the "owning" processor is also always generating the
  correct entries, so PETSc need not ship over the duplicate entry
  generated on another processor. -
- Added options MAT_COLUMNS_UNSORTED and MAT_ROWS_UNSORTED for
  MatSetOption() to enable switching betwen sorted and unsorted
  input.

```{rubric} DA (Distributed Arrays):
```

```{rubric} VEC (Vectors):
```

- Changed the SCATTER_ALL argument in VecScatterXXX() routines to
  SCATTER_FORWARD.
- Added the routines VecSetValuesLocal() and
  VecSetLocalToGlobalMapping() to allow the user to set values into
  a vector using a local numbering of the nodes rather than a global
  numbering.
- Added the routine
  VecSetOption(Vec,VEC_IGNORE_OFF_PROCESSOR_ENTRIES,PETSC_TRUE),
  which causes all entries on any processor destined to be stored on
  a different processor to be dropped instead. This is useful if you
  know that the "owning" processor is also always generating the
  correct entries, so PETSc need not transfer the duplicate entries
  generated on another processor.

```{rubric} IS (Index Sets):
```

```{rubric} Draw (Graphics):
```

- The numbers on the axis plots are much improved.
- You can now pass PETSC_DECIDE as the x and y arguments in
  DrawOpenX() and ViewerDrawOpenX() to let PETSc place
  non-overlapping windows on the display.

```{rubric} Viewers:
```

```{rubric} System Routines:
```

- Added routines PetscSynchronizedPrintf(MPI_Comm,format,args) and
  PetscSynchronizedFlush(MPI_Comm), which allow groups of processes
  to print to stdout as one would expect. I.e., the output from
  processor 0 is followed by the output from processor 1, etc. Very
  useful during code development. This can often be a substitute for
  attempting to sequentialize printf() statements via
  PetscSequentialPhaseBegin() and PetscSequentialPhaseEnd(). -
- Added the command line option -options_file \<file> that causes all
  options in the specified file to be treated as if they were typed
  on the command line.
- Added the option -log_trace [filename] (and the corresponding
  routine PLogTraceBegin()) that allows tracing of all PETSc calls;
  useful to see where a program is hanging without running in the
  debugger. Can be used in conjunction with the -log_info option.
- Added PetscRandomSetInterval() to enable the user to set an
  interval over which random numbers will be uniformly distributed.

```{rubric} Event Logging:
```

```{rubric} Fortran Interface:
```

- Added the Fortran interface for VecDuplicateVecs(),
  VecDestroyVecs(), VecMAXPY(), VecMDot(), and VecMTDot().
