Reference documentation for deal.II version Git 497f915867 20210917 22:46:48 +0200

#include <deal.II/lac/petsc_vector.h>
Public Types  
using  size_type = types::global_dof_index 
using  value_type = PetscScalar 
using  real_type = PetscReal 
using  reference = internal::VectorReference 
using  const_reference = const internal::VectorReference 
Public Member Functions  
Vector ()  
Vector (const MPI_Comm &communicator, const size_type n, const size_type locally_owned_size)  
template<typename Number >  
Vector (const MPI_Comm &communicator, const ::Vector< Number > &v, const size_type locally_owned_size)  
Vector (const MPI_Comm &communicator, const VectorBase &v, const size_type local_size)  
Vector (const IndexSet &local, const IndexSet &ghost, const MPI_Comm &communicator)  
Vector (const IndexSet &local, const MPI_Comm &communicator)  
Vector (const Vector &v)  
virtual void  clear () override 
Vector &  operator= (const Vector &v) 
Vector &  operator= (const PetscScalar s) 
template<typename number >  
Vector &  operator= (const ::Vector< number > &v) 
void  reinit (const MPI_Comm &communicator, const size_type N, const size_type locally_owned_size, const bool omit_zeroing_entries=false) 
void  reinit (const Vector &v, const bool omit_zeroing_entries=false) 
void  reinit (const IndexSet &local, const IndexSet &ghost, const MPI_Comm &communicator) 
void  reinit (const IndexSet &local, const MPI_Comm &communicator) 
const MPI_Comm &  get_mpi_communicator () const override 
void  print (std::ostream &out, const unsigned int precision=3, const bool scientific=true, const bool across=true) const 
bool  all_zero () const 
void  compress (const VectorOperation::values operation) 
bool  operator== (const VectorBase &v) const 
bool  operator!= (const VectorBase &v) const 
size_type  size () const 
size_type  local_size () const 
size_type  locally_owned_size () const 
std::pair< size_type, size_type >  local_range () const 
bool  in_local_range (const size_type index) const 
IndexSet  locally_owned_elements () const 
bool  has_ghost_elements () const 
void  update_ghost_values () const 
reference  operator() (const size_type index) 
PetscScalar  operator() (const size_type index) const 
reference  operator[] (const size_type index) 
PetscScalar  operator[] (const size_type index) const 
void  set (const std::vector< size_type > &indices, const std::vector< PetscScalar > &values) 
void  extract_subvector_to (const std::vector< size_type > &indices, std::vector< PetscScalar > &values) const 
template<typename ForwardIterator , typename OutputIterator >  
void  extract_subvector_to (const ForwardIterator indices_begin, const ForwardIterator indices_end, OutputIterator values_begin) const 
void  add (const std::vector< size_type > &indices, const std::vector< PetscScalar > &values) 
void  add (const std::vector< size_type > &indices, const ::Vector< PetscScalar > &values) 
void  add (const size_type n_elements, const size_type *indices, const PetscScalar *values) 
void  add (const PetscScalar s) 
void  add (const PetscScalar a, const VectorBase &V) 
void  add (const PetscScalar a, const VectorBase &V, const PetscScalar b, const VectorBase &W) 
PetscScalar  operator* (const VectorBase &vec) const 
real_type  norm_sqr () const 
PetscScalar  mean_value () const 
real_type  l1_norm () const 
real_type  l2_norm () const 
real_type  lp_norm (const real_type p) const 
real_type  linfty_norm () const 
PetscScalar  add_and_dot (const PetscScalar a, const VectorBase &V, const VectorBase &W) 
real_type  min () const 
real_type  max () const 
bool  is_non_negative () const 
VectorBase &  operator*= (const PetscScalar factor) 
VectorBase &  operator/= (const PetscScalar factor) 
VectorBase &  operator+= (const VectorBase &V) 
VectorBase &  operator= (const VectorBase &V) 
void  sadd (const PetscScalar s, const VectorBase &V) 
void  sadd (const PetscScalar s, const PetscScalar a, const VectorBase &V) 
void  scale (const VectorBase &scaling_factors) 
void  equ (const PetscScalar a, const VectorBase &V) 
void  write_ascii (const PetscViewerFormat format=PETSC_VIEWER_DEFAULT) 
void  swap (VectorBase &v) 
operator const Vec & () const  
std::size_t  memory_consumption () const 
template<class Archive >  
void  serialize (Archive &ar, const unsigned int version) 
Subscriptor functionality  
Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.  
void  subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const 
void  unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const 
unsigned int  n_subscriptions () const 
template<typename StreamType >  
void  list_subscribers (StreamType &stream) const 
void  list_subscribers () const 
Static Public Member Functions  
static ::ExceptionBase &  ExcInUse (int arg1, std::string arg2, std::string arg3) 
static ::ExceptionBase &  ExcNoSubscriber (std::string arg1, std::string arg2) 
Protected Member Functions  
virtual void  create_vector (const size_type n, const size_type locally_owned_size) 
virtual void  create_vector (const size_type n, const size_type locally_owned_size, const IndexSet &ghostnodes) 
void  do_set_add_operation (const size_type n_elements, const size_type *indices, const PetscScalar *values, const bool add_values) 
Protected Attributes  
Vec  vector 
bool  ghosted 
IndexSet  ghost_indices 
VectorOperation::values  last_action 
bool  obtained_ownership 
Private Attributes  
MPI_Comm  communicator 
Related Functions  
(Note that these are not member functions.)  
void  swap (Vector &u, Vector &v) 
void  swap (VectorBase &u, VectorBase &v) 
Implementation of a parallel vector class based on PETSC and using MPI communication to synchronize distributed operations. All the functionality is actually in the base class, except for the calls to generate a parallel vector. This is possible since PETSc only works on an abstract vector type and internally distributes to functions that do the actual work depending on the actual vector type (much like using virtual functions). Only the functions creating a vector of specific type differ, and are implemented in this particular class.
The parallel functionality of PETSc is built on top of the Message Passing Interface (MPI). MPI's communication model is built on collective communications: if one process wants something from another, that other process has to be willing to accept this communication. A process cannot query data from another process by calling a remote function, without that other process expecting such a transaction. The consequence is that most of the operations in the base class of this class have to be called collectively. For example, if you want to compute the l2 norm of a parallel vector, all processes across which this vector is shared have to call the l2_norm
function. If you don't do this, but instead only call the l2_norm
function on one process, then the following happens: This one process will call one of the collective MPI functions and wait for all the other processes to join in on this. Since the other processes don't call this function, you will either get a timeout on the first process, or, worse, by the time the next a call to a PETSc function generates an MPI message on the other processes, you will get a cryptic message that only a subset of processes attempted a communication. These bugs can be very hard to figure out, unless you are wellacquainted with the communication model of MPI, and know which functions may generate MPI messages.
One particular case, where an MPI message may be generated unexpectedly is discussed below.
PETSc does allow read access to individual elements of a vector, but in the distributed case only to elements that are stored locally. We implement this through calls like d=vec(i)
. However, if you access an element outside the locally stored range, an exception is generated.
In contrast to read access, PETSc (and the respective deal.II wrapper classes) allow to write (or add) to individual elements of vectors, even if they are stored on a different process. You can do this writing, for example, vec(i)=d
or vec(i)+=d
, or similar operations. There is one catch, however, that may lead to very confusing error messages: PETSc requires application programs to call the compress() function when they switch from adding, to elements to writing to elements. The reasoning is that all processes might accumulate addition operations to elements, even if multiple processes write to the same elements. By the time we call compress() the next time, all these additions are executed. However, if one process adds to an element, and another overwrites to it, the order of execution would yield nondeterministic behavior if we don't make sure that a synchronization with compress() happens in between.
In order to make sure these calls to compress() happen at the appropriate time, the deal.II wrappers keep a state variable that store which is the presently allowed operation: additions or writes. If it encounters an operation of the opposite kind, it calls compress() and flips the state. This can sometimes lead to very confusing behavior, in code that may for example look like this:
This code can run into trouble: by the time we see the first addition operation, we need to flush the overwrite buffers for the vector, and the deal.II library will do so by calling compress(). However, it will only do so for all processes that actually do an addition – if the condition is never true for one of the processes, then this one will not get to the actual compress() call, whereas all the other ones do. This gets us into trouble, since all the other processes hang in the call to flush the write buffers, while the one other process advances to the call to compute the l2 norm. At this time, you will get an error that some operation was attempted by only a subset of processes. This behavior may seem surprising, unless you know that write/addition operations on single elements may trigger this behavior.
The problem described here may be avoided by placing additional calls to compress(), or making sure that all processes do the same type of operations at the same time, for example by placing zero additions if necessary.
Definition at line 156 of file petsc_vector.h.
Declare type for container size.
Definition at line 162 of file petsc_vector.h.

inherited 
Declare some of the standard types used in all containers. These types parallel those in the C++
standard libraries vector<...>
class.
Definition at line 258 of file petsc_vector_base.h.

inherited 
Definition at line 259 of file petsc_vector_base.h.

inherited 
Definition at line 261 of file petsc_vector_base.h.

inherited 
Definition at line 262 of file petsc_vector_base.h.
Default constructor. Initialize the vector as empty.
Definition at line 31 of file petsc_parallel_vector.cc.

explicit 
Constructor. Set dimension to n
and initialize all elements with zero.
The constructor is made explicit to avoid accidents like this: v=0;
. Presumably, the user wants to set every element of the vector to zero, but instead, what happens is this call: v=Vector<number>(0);
, i.e. the vector is replaced by one of length zero.
Definition at line 42 of file petsc_parallel_vector.cc.

explicit 
Copyconstructor from deal.II vectors. Sets the dimension to that of the given vector, and copies all elements.

explicit 
Copyconstructor the values from a PETSc wrapper vector class.
Definition at line 52 of file petsc_parallel_vector.cc.
Vector< Number >::Vector  (  const IndexSet &  local, 
const IndexSet &  ghost,  
const MPI_Comm &  communicator  
) 
Construct a new parallel ghosted PETSc vector from IndexSets.
Note that local
must be ascending and 1:1, see IndexSet::is_ascending_and_one_to_one(). In particular, the DoFs in local
need to be contiguous, meaning you can only create vectors from a DoFHandler with several finite element components if they are not reordered by component (use a PETScWrappers::BlockVector otherwise). The global size of the vector is determined by local.size(). The global indices in ghost
are supplied as ghost indices so that they can be read locally.
Note that the ghost
IndexSet may be empty and that any indices already contained in local
are ignored during construction. That way, the ghost parameter can equal the set of locally relevant degrees of freedom, see step32.
Definition at line 72 of file petsc_parallel_vector.cc.
Construct a new parallel PETSc vector without ghost elements from an IndexSet.
Note that local
must be ascending and 1:1, see IndexSet::is_ascending_and_one_to_one(). In particular, the DoFs in local
need to be contiguous, meaning you can only create vectors from a DoFHandler with several finite element components if they are not reordered by component (use a PETScWrappers::BlockVector otherwise).
Definition at line 104 of file petsc_parallel_vector.cc.
Copy constructor.
Definition at line 88 of file petsc_parallel_vector.cc.

overridevirtual 
Release all memory and return to a state just like after having called the default constructor.
Reimplemented from PETScWrappers::VectorBase.
Definition at line 152 of file petsc_parallel_vector.cc.
Copy the given vector. Resize the present vector if necessary. Also take over the MPI communicator of v
.
Definition at line 115 of file petsc_parallel_vector.cc.
Vector& PETScWrappers::MPI::Vector::operator=  (  const PetscScalar  s  ) 
Set all components of the vector to the given number s
. Simply pass this down to the base class, but we still need to declare this function to make the example given in the discussion about making the constructor explicit work.
Vector& PETScWrappers::MPI::Vector::operator=  (  const ::Vector< number > &  v  ) 
Copy the values of a deal.II vector (as opposed to those of the PETSc vector wrapper class) into this object.
Contrary to the case of sequential vectors, this operators requires that the present vector already has the correct size, since we need to have a partition and a communicator present which we otherwise can't get from the source vector.
void Vector< Number >::reinit  (  const MPI_Comm &  communicator, 
const size_type  N,  
const size_type  locally_owned_size,  
const bool  omit_zeroing_entries = false 

) 
Change the dimension of the vector to N
. It is unspecified how resizing the vector affects the memory allocation of this object; i.e., it is not guaranteed that resizing it to a smaller size actually also reduces memory consumption, or if for efficiency the same amount of memory is used
locally_owned_size
denotes how many of the N
values shall be stored locally on the present process. for less data.
communicator
denotes the MPI communicator henceforth to be used for this vector.
If omit_zeroing_entries
is false, the vector is filled by zeros. Otherwise, the elements are left an unspecified state.
Definition at line 163 of file petsc_parallel_vector.cc.
Change the dimension to that of the vector v
, and also take over the partitioning into local sizes as well as the MPI communicator. The same applies as for the other reinit
function.
The elements of v
are not copied, i.e. this function is the same as calling reinit(v.size(), v.locally_owned_size(), omit_zeroing_entries)
.
Definition at line 206 of file petsc_parallel_vector.cc.
void Vector< Number >::reinit  (  const IndexSet &  local, 
const IndexSet &  ghost,  
const MPI_Comm &  communicator  
) 
Reinit as a vector with ghost elements. See the constructor with same signature for more details.
Definition at line 227 of file petsc_parallel_vector.cc.
Reinit as a vector without ghost elements. See constructor with same signature for more details.
Definition at line 245 of file petsc_parallel_vector.cc.

overridevirtual 
Return a reference to the MPI communicator object in use with this vector.
Reimplemented from PETScWrappers::VectorBase.
void Vector< Number >::print  (  std::ostream &  out, 
const unsigned int  precision = 3 , 

const bool  scientific = true , 

const bool  across = true 

)  const 
Print to a stream. precision
denotes the desired precision with which values shall be printed, scientific
whether scientific notation shall be used. If across
is true
then the vector is printed in a line, while if false
then the elements are printed on a separate line each.
Definition at line 363 of file petsc_parallel_vector.cc.
Return whether the vector contains only elements with value zero. This is a collective operation. This function is expensive, because potentially all elements have to be checked.
Definition at line 348 of file petsc_parallel_vector.cc.

protectedvirtual 
Create a vector of length n
. For this class, we create a parallel vector. n
denotes the total size of the vector to be created. locally_owned_size
denotes how many of these elements shall be stored locally.
Definition at line 259 of file petsc_parallel_vector.cc.

protectedvirtual 
Create a vector of global length n
, local size locally_owned_size
and with the specified ghost indices. Note that you need to call update_ghost_values() before accessing those.
Definition at line 277 of file petsc_parallel_vector.cc.

inherited 
Compress the underlying representation of the PETSc object, i.e. flush the buffers of the vector object if it has any. This function is necessary after writing into a vector elementbyelement and before anything else can be done on it.
See Compressing distributed objects for more information.
Definition at line 379 of file petsc_vector_base.cc.

inherited 
Test for equality. This function assumes that the present vector and the one to compare with have the same size already, since comparing vectors of different sizes makes not much sense anyway.
Definition at line 226 of file petsc_vector_base.cc.

inherited 
Test for inequality. This function assumes that the present vector and the one to compare with have the same size already, since comparing vectors of different sizes makes not much sense anyway.
Definition at line 240 of file petsc_vector_base.cc.

inherited 
Return the global dimension of the vector.
Definition at line 254 of file petsc_vector_base.cc.

inherited 
Return the local dimension of the vector, i.e. the number of elements stored on the present MPI process. For sequential vectors, this number is the same as size(), but for parallel vectors it may be smaller.
To figure out which elements exactly are stored locally, use local_range() or locally_owned_elements().
Definition at line 278 of file petsc_vector_base.cc.

inherited 
Return the local dimension of the vector, i.e. the number of elements stored on the present MPI process. For sequential vectors, this number is the same as size(), but for parallel vectors it may be smaller.
To figure out which elements exactly are stored locally, use local_range() or locally_owned_elements().
Definition at line 266 of file petsc_vector_base.cc.

inherited 
Return a pair of indices indicating which elements of this vector are stored locally. The first number is the index of the first element stored, the second the index of the one past the last one that is stored locally. If this is a sequential vector, then the result will be the pair (0,N), otherwise it will be a pair (i,i+n), where n=locally_owned_size()
.
Definition at line 290 of file petsc_vector_base.cc.
Return whether index
is in the local range or not, see also local_range().

inherited 
Return an index set that describes which elements of this vector are owned by the current processor. Note that this index set does not include elements this vector may store locally as ghost elements but that are in fact owned by another processor. As a consequence, the index sets returned on different processors if this is a distributed vector will form disjoint sets that add up to the complete index set. Obviously, if a vector is created on only one processor, then the result would satisfy

inherited 
Return if the vector contains ghost elements.

inherited 
This function only exists for compatibility with the LinearAlgebra::distributed::Vector
class and does nothing: this class implements ghost value updates in a different way that is a better fit with the underlying PETSc vector object.
Provide access to a given element, both read and write.

inherited 
Provide readonly access to an element.
Provide access to a given element, both read and write.
Exactly the same as operator().

inherited 
Provide readonly access to an element.
Exactly the same as operator().

inherited 
A collective set operation: instead of setting individual elements of a vector, this function allows to set a whole set of elements at once. The indices of the elements to be set are stated in the first argument, the corresponding values in the second.
Definition at line 303 of file petsc_vector_base.cc.

inherited 
Instead of getting individual elements of a vector via operator(), this function allows getting a whole set of elements at once. The indices of the elements to be read are stated in the first argument, the corresponding values are returned in the second.
If the current vector is called v
, then this function is the equivalent to the code
indices
and values
arrays must be identical.

inherited 
Instead of getting individual elements of a vector via operator(), this function allows getting a whole set of elements at once. In contrast to the previous function, this function obtains the indices of the elements by dereferencing all elements of the iterator range provided by the first two arguments, and puts the vector values into memory locations obtained by dereferencing a range of iterators starting at the location pointed to by the third argument.
If the current vector is called v
, then this function is the equivalent to the code
values_begin
as there are iterators between indices_begin
and indices_end
.

inherited 
A collective add operation: This function adds a whole set of values stored in values
to the vector components specified by indices
.
Definition at line 314 of file petsc_vector_base.cc.

inherited 
This is a second collective add operation. As a difference, this function takes a deal.II vector of values.
Definition at line 325 of file petsc_vector_base.cc.

inherited 
Take an address where n_elements
are stored contiguously and add them into the vector. Handles all cases which are not covered by the other two add()
functions above.
Definition at line 336 of file petsc_vector_base.cc.

inherited 
Addition of s
to all components. Note that s
is a scalar and not a vector.
Definition at line 748 of file petsc_vector_base.cc.

inherited 
Simple addition of a multiple of a vector, i.e. *this += a*V
.
Definition at line 760 of file petsc_vector_base.cc.

inherited 
Multiple addition of scaled vectors, i.e. *this += a*V+b*W
.
Definition at line 772 of file petsc_vector_base.cc.

inherited 
Return the scalar product of two vectors. The vectors must have the same size.
For complex valued vector, this gives \(\left(v^\ast,vec\right)\).
Definition at line 346 of file petsc_vector_base.cc.

inherited 
Return the square of the \(l_2\)norm.
Definition at line 439 of file petsc_vector_base.cc.

inherited 
Return the mean value of the elements of this vector.
Definition at line 448 of file petsc_vector_base.cc.

inherited 
\(l_1\)norm of the vector. The sum of the absolute values.
Definition at line 499 of file petsc_vector_base.cc.

inherited 
\(l_2\)norm of the vector. The square root of the sum of the squares of the elements.
Definition at line 512 of file petsc_vector_base.cc.

inherited 
\(l_p\)norm of the vector. The pth root of the sum of the pth powers of the absolute values of the elements.
Definition at line 525 of file petsc_vector_base.cc.

inherited 
\(l_\infty\)norm of the vector. Return the value of the vector element with the maximum absolute value.
Definition at line 567 of file petsc_vector_base.cc.

inherited 
Performs a combined operation of a vector addition and a subsequent inner product, returning the value of the inner product. In other words, the result of this function is the same as if the user called
The reason this function exists is for compatibility with deal.II's own vector classes which can implement this functionality with less memory transfer. However, for PETSc vectors such a combined operation is not natively supported and thus the cost is completely equivalent as calling the two methods separately.
For complexvalued vectors, the scalar product in the second step is implemented as \(\left<v,w\right>=\sum_i v_i \bar{w_i}\).
Definition at line 368 of file petsc_vector_base.cc.

inherited 
Return the value of the vector element with the largest negative value.
Definition at line 580 of file petsc_vector_base.cc.

inherited 
Return the value of the vector element with the largest positive value.
Definition at line 593 of file petsc_vector_base.cc.

inherited 
Return true
if the vector has no negative entries, i.e. all entries are zero or positive. This function is used, for example, to check whether refinement indicators are really all positive (or zero).
Definition at line 661 of file petsc_vector_base.cc.

inherited 
Multiply the entire vector by a fixed factor.
Definition at line 693 of file petsc_vector_base.cc.

inherited 
Divide the entire vector by a fixed factor.
Definition at line 707 of file petsc_vector_base.cc.

inherited 
Add the given vector to the present one.
Definition at line 724 of file petsc_vector_base.cc.

inherited 
Subtract the given vector from the present one.
Definition at line 736 of file petsc_vector_base.cc.

inherited 
Scaling and simple vector addition, i.e. *this = s*(*this)+V
.
Definition at line 791 of file petsc_vector_base.cc.

inherited 
Scaling and simple addition, i.e. *this = s*(*this)+a*V
.
Definition at line 803 of file petsc_vector_base.cc.

inherited 
Scale each element of this vector by the corresponding element in the argument. This function is mostly meant to simulate multiplication (and immediate reassignment) by a diagonal scaling matrix.
Definition at line 821 of file petsc_vector_base.cc.

inherited 
Assignment *this = a*V
.
Definition at line 831 of file petsc_vector_base.cc.

inherited 
Prints the PETSc vector object values using PETSc internal vector viewer function VecView
. The default format prints the vector's contents, including indices of vector elements. For other valid view formats, consult http://www.mcs.anl.gov/petsc/petsccurrent/docs/manualpages/Vec/VecView.html
Definition at line 850 of file petsc_vector_base.cc.

inherited 
Swap the contents of this vector and the other vector v
. One could do this operation with a temporary variable and copying over the data elements, but this function is significantly more efficient since it only swaps the pointers to the data of the two vectors and therefore does not need to allocate temporary storage and move data around.
This function is analogous to the swap
function of all C++ standard containers. Also, there is a global function swap(u,v)
that simply calls u.swap(v)
, again in analogy to standard functions.
Definition at line 914 of file petsc_vector_base.cc.

inherited 
Conversion operator to gain access to the underlying PETSc type. If you do this, you cut this class off some information it may need, so this conversion operator should only be used if you know what you do. In particular, it should only be used for readonly operations into the vector.
Definition at line 922 of file petsc_vector_base.cc.

inherited 
Estimate for the memory consumption (not implemented for this class).
Definition at line 929 of file petsc_vector_base.cc.

protectedinherited 
Collective set or add operation: This function is invoked by the collective set
and add
with the add_values
flag set to the corresponding value.
Definition at line 951 of file petsc_vector_base.cc.

inherited 
Subscribes a user of the object by storing the pointer validity
. The subscriber may be identified by text supplied as identifier
.
Definition at line 136 of file subscriptor.cc.

inherited 
Unsubscribes a user from the object.
identifier
and the validity
pointer must be the same as the one supplied to subscribe(). Definition at line 156 of file subscriptor.cc.

inlineinherited 
Return the present number of subscriptions to this object. This allows to use this class for reference counted lifetime determination where the last one to unsubscribe also deletes the object.
Definition at line 301 of file subscriptor.h.

inlineinherited 
List the subscribers to the input stream
.
Definition at line 318 of file subscriptor.h.

inherited 
List the subscribers to deallog
.
Definition at line 204 of file subscriptor.cc.

inlineinherited 
Read or write the data of this object to or from a stream for the purpose of serialization using the BOOST serialization library.
This function does not actually serialize any of the member variables of this class. The reason is that what this class stores is only who subscribes to this object, but who does so at the time of storing the contents of this object does not necessarily have anything to do with who subscribes to the object when it is restored. Consequently, we do not want to overwrite the subscribers at the time of restoring, and then there is no reason to write the subscribers out in the first place.
Definition at line 310 of file subscriptor.h.
Global function swap
which overloads the default implementation of the C++ standard library which uses a temporary object. The function simply exchanges the data of the two vectors.
Definition at line 434 of file petsc_vector.h.

related 
Global function swap
which overloads the default implementation of the C++ standard library which uses a temporary object. The function simply exchanges the data of the two vectors.
Definition at line 856 of file petsc_vector_base.h.

private 
Copy of the communicator object to be used for this parallel vector.
Definition at line 419 of file petsc_vector.h.

protectedinherited 
A generic vector object in PETSc. The actual type, a sequential vector, is set in the constructor.
Definition at line 799 of file petsc_vector_base.h.

protectedinherited 
Denotes if this vector has ghost indices associated with it. This means that at least one of the processes in a parallel program has at least one ghost index.
Definition at line 806 of file petsc_vector_base.h.

protectedinherited 
This vector contains the global indices of the ghost values. The location in this vector denotes the local numbering, which is used in PETSc.
Definition at line 813 of file petsc_vector_base.h.

mutableprotectedinherited 
Store whether the last action was a write or add operation. This variable is mutable
so that the accessor classes can write to it, even though the vector object they refer to is constant.
Definition at line 820 of file petsc_vector_base.h.

protectedinherited 
Specifies if the vector is the owner of the PETSc Vec. This is true if it got created by this class and determines if it gets destroyed in the destructor.
Definition at line 830 of file petsc_vector_base.h.