PETScWrappers::MPI::BlockVector Class Reference
[PETScWrappersVector classes]

Inheritance diagram for PETScWrappers::MPI::BlockVector:
Inheritance graph
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List of all members.

Classes

class  ExcIteratorRangeDoesNotMatchVectorSize
class  ExcNonMatchingBlockVectors

Public Types

typedef BlockVectorBase< VectorBaseClass
typedef BaseClass::BlockType BlockType
typedef BaseClass::value_type value_type
typedef BaseClass::pointer pointer
typedef BaseClass::const_pointer const_pointer
typedef BaseClass::reference reference
typedef BaseClass::const_reference const_reference
typedef BaseClass::size_type size_type
typedef BaseClass::iterator iterator
typedef BaseClass::const_iterator const_iterator

Public Member Functions

 BlockVector ()
 BlockVector (const unsigned int n_blocks, const MPI_Comm &communicator, const unsigned int block_size, const unsigned int local_size)
 BlockVector (const BlockVector &V)
 BlockVector (const std::vector< unsigned int > &block_sizes, const MPI_Comm &communicator, const std::vector< unsigned int > &local_elements)
 ~BlockVector ()
BlockVectoroperator= (const value_type s)
BlockVectoroperator= (const BlockVector &V)
BlockVectoroperator= (const PETScWrappers::BlockVector &v)
void reinit (const unsigned int n_blocks, const MPI_Comm &communicator, const unsigned int block_size, const unsigned int local_size, const bool fast=false)
void reinit (const std::vector< unsigned int > &block_sizes, const MPI_Comm &communicator, const std::vector< unsigned int > &local_sizes, const bool fast=false)
void reinit (const BlockVector &V, const bool fast=false)
const MPI_Comm & get_mpi_communicator () const
void swap (BlockVector &v)

Detailed Description

An implementation of block vectors based on the parallel vector class implemented in PETScWrappers. While the base class provides for most of the interface, this class handles the actual allocation of vectors and provides functions that are specific to the underlying vector type.

The model of distribution of data is such that each of the blocks is distributed across all MPI processes named in the MPI communicator. I.e. we don't just distribute the whole vector, but each component. In the constructors and reinit() functions, one therefore not only has to specify the sizes of the individual blocks, but also the number of elements of each of these blocks to be stored on the local process.

Author:
Wolfgang Bangerth, 2004

Member Typedef Documentation

Typedef the base class for simpler access to its own typedefs.

Typedef the type of the underlying vector.

Reimplemented from BlockVectorBase< Vector >.

Import the typedefs from the base class.

Reimplemented from BlockVectorBase< Vector >.

Reimplemented from BlockVectorBase< Vector >.

Reimplemented from BlockVectorBase< Vector >.

Reimplemented from BlockVectorBase< Vector >.

Reimplemented from BlockVectorBase< Vector >.

Reimplemented from BlockVectorBase< Vector >.

Reimplemented from BlockVectorBase< Vector >.

Reimplemented from BlockVectorBase< Vector >.


Constructor & Destructor Documentation

BlockVector< Number >::BlockVector (  )  [inline]

Default constructor. Generate an empty vector without any blocks.

BlockVector< Number >::BlockVector ( const unsigned int  n_blocks,
const MPI_Comm &  communicator,
const unsigned int  block_size,
const unsigned int  local_size 
) [inline, explicit]

Constructor. Generate a block vector with n_blocks blocks, each of which is a parallel vector across communicator with block_size elements of which local_size elements are stored on the present process.

References reinit().

BlockVector< Number >::BlockVector ( const BlockVector V  )  [inline]
BlockVector< Number >::BlockVector ( const std::vector< unsigned int > &  block_sizes,
const MPI_Comm &  communicator,
const std::vector< unsigned int > &  local_elements 
) [inline]

Constructor. Set the number of blocks to block_sizes.size() and initialize each block with block_sizes[i] zero elements. The individual blocks are distributed across the given communicator, and each store local_elements[i] elements on the present process.

References reinit().

BlockVector< Number >::~BlockVector (  )  [inline]

Destructor. Clears memory


Member Function Documentation

BlockVector & BlockVector< Number >::operator= ( const value_type  s  )  [inline]

Copy operator: fill all components of the vector that are locally stored with the given scalar value.

References BlockVectorBase< Vector >::operator=().

BlockVector & BlockVector< Number >::operator= ( const BlockVector V  )  [inline]

Copy operator for arguments of the same type.

Reimplemented from Subscriptor.

References BlockVectorBase< Vector >::operator=().

BlockVector& PETScWrappers::MPI::BlockVector::operator= ( const PETScWrappers::BlockVector v  ) 

Copy the given sequential (non-distributed) block vector into the present parallel block vector. It is assumed that they have the same size, and this operation does not change the partitioning of the parallel vectors by which its elements are distributed across several MPI processes. What this operation therefore does is to copy that chunk of the given vector v that corresponds to elements of the target vector that are stored locally, and copies them, for each of the individual blocks of this object. Elements that are not stored locally are not touched.

This being a parallel vector, you must make sure that all processes call this function at the same time. It is not possible to change the local part of a parallel vector on only one process, independent of what other processes do, with this function.

void BlockVector< Number >::reinit ( const unsigned int  n_blocks,
const MPI_Comm &  communicator,
const unsigned int  block_size,
const unsigned int  local_size,
const bool  fast = false 
) [inline]

Reinitialize the BlockVector to contain n_blocks of size block_size, each of which stores local_size elements locally. The communicator argument denotes which MPI channel each of these blocks shall communicate.

If fast==false, the vector is filled with zeros.

Referenced by BlockVector(), and reinit().

void BlockVector< Number >::reinit ( const std::vector< unsigned int > &  block_sizes,
const MPI_Comm &  communicator,
const std::vector< unsigned int > &  local_sizes,
const bool  fast = false 
) [inline]

Reinitialize the BlockVector such that it contains block_sizes.size() blocks. Each block is reinitialized to dimension block_sizes[i]. Each of them stores local_sizes[i] elements on the present process.

If the number of blocks is the same as before this function was called, all vectors remain the same and reinit() is called for each vector.

If fast==false, the vector is filled with zeros.

Note that you must call this (or the other reinit() functions) function, rather than calling the reinit() functions of an individual block, to allow the block vector to update its caches of vector sizes. If you call reinit() of one of the blocks, then subsequent actions on this object may yield unpredictable results since they may be routed to the wrong block.

References BlockVectorBase< Vector >::block_indices, BlockVectorBase< Vector >::components, BlockVectorBase< Vector >::n_blocks(), reinit(), and BlockIndices::reinit().

void BlockVector< Number >::reinit ( const BlockVector V,
const bool  fast = false 
) [inline]

Change the dimension to that of the vector V. 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(), fast).

Note that you must call this (or the other reinit() functions) function, rather than calling the reinit() functions of an individual block, to allow the block vector to update its caches of vector sizes. If you call reinit() on one of the blocks, then subsequent actions on this object may yield unpredictable results since they may be routed to the wrong block.

References BlockVectorBase< VectorType >::block(), BlockVectorBase< Vector >::block(), BlockVectorBase< Vector >::block_indices, BlockVectorBase< Vector >::components, BlockVectorBase< VectorType >::get_block_indices(), BlockVectorBase< Vector >::n_blocks(), and Vector< Number >::reinit().

const MPI_Comm & BlockVector< Number >::get_mpi_communicator (  )  const [inline]

Return a reference to the MPI communicator object in use with this vector.

References BlockVectorBase< Vector >::block().

void BlockVector< Number >::swap ( BlockVector v  )  [inline]

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.

Limitation: right now this function only works if both vectors have the same number of blocks. If needed, the numbers of blocks should be exchanged, too.

This function is analog to the 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.

References Assert, BlockVectorBase< VectorType >::block_indices, BlockVectorBase< Vector >::block_indices, BlockVectorBase< VectorType >::components, BlockVectorBase< Vector >::components, BlockVectorBase< VectorType >::n_blocks(), BlockVectorBase< Vector >::n_blocks(), and swap().


The documentation for this class was generated from the following file:

deal.II documentation generated on Mon Nov 23 22:58:31 2009 by doxygen 1.6.1