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matrixview< T > Class Template Reference
[Data blocks and data views]

A two-dimensional view of a data block, suitable for a BLAS-compatible matrix. NO DOC YET! More...

#include <dataview.h>

Inherits dataview_interface< T >< T >.

Inherited by DenseMatrix< T >.

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List of all members.

Public Member Functions

 matrixview (datablock< T > *db, const itype e[2], const itype r[2], const itype o[2])
 matrixview (const matrixview< T > &other)
void initialize (const datablock< T > *db, const itype e[2], const itype r[2], const itype o[2])
virtual bool Valid () const
 Should return TRUE if and only if the view has been properly initialized. Doesn't check parameters for sanity!
virtual datablock< T > * GetDataBlock () const
 Each dataview is attached to a datablock; this should give access to it. Only usable from derived classes (i.e., views).
virtual itype Dimensionality () const
 Should return the number of indices required to define an element in this view.
virtual itype Size () const
 Should return the total size of the view -- i.e., the product of the virtual ranges.
virtual itype Range (itype i) const
 Should return the virtual range of index i.
virtual bool Is1DCompatible () const
 Should return TRUE if and only if this view provides 1-D strided access.
virtual bool Is2DCompatible () const
 Should return TRUE if and only if this view provides 2-D semi-contiguous strided access.
virtual T * Get1DRep (itype &n_elements, itype &r_stride) const
virtual T * Get2DRep (itype &n_series, itype &series_size, itype &series_extent) const
virtual T & item (itype index) const
virtual T & element (itype *iarr) const
virtual T & element (itype i1,...) const
virtual void PrettyPrint (std::ostream &os=std::cout) const
virtual void DataPrint (std::ostream &os=std::cout) const
virtual void OwnData (bool copyflag)
virtual void FillFromStream (std::istream &is, bool clear=true)
virtual void InitFromStream (std::istream &is)
itype Rows () const
itype Columns () const
matrixview< T > GetSubMatrixView (interval sub_R, interval sub_C) const
vectorview< T > GetRowVectorView (itype r) const
vectorview< T > GetColumnVectorView (itype c) const
matrixview< T > copy () const
T & operator() (itype i1, itype i2) const
T & operator() (itype i) const
virtual void Fill (T val)
void SetSize (itype s1, itype s2, bool copyflag)

Protected Member Functions

void CreateSubMatrixView (interval sub_R, interval sub_C, matrixview< T > &sm) const
void CreateRowVectorView (itype r, vectorview< T > &rv) const
void CreateColumnVectorView (itype c, vectorview< T > &cv) const

Detailed Description

template<class T>
class matrixview< T >

A two-dimensional view of a data block, suitable for a BLAS-compatible matrix. NO DOC YET!


Member Function Documentation

template<class T>
virtual bool matrixview< T >::Is1DCompatible  )  const [inline, virtual]
 

Should return TRUE if and only if this view provides 1-D strided access.

In other words, the data elements must be evenly spaced -- spacing of 1 means contiguous. There must exist a T* ptr and an int K such that every element X of the view is accessible as X = ptr[ N * K ] for some N in {0...Size()-1}.

Implements dataview_interface< T >.

template<class T>
virtual bool matrixview< T >::Is2DCompatible  )  const [inline, virtual]
 

Should return TRUE if and only if this view provides 2-D semi-contiguous strided access.

In other words, the data must be arranged in evenly spaced blocks, e.g. as blocks of length L followed by gaps of length K-L. There must exist a T* ptr and int K such that every element X of the view is accessible as X = ptr[ M + N * K ] for some N,M.

Implements dataview_interface< T >.

template<typename T>
T * matrixview< T >::Get1DRep itype n_elements,
itype r_stride
const [virtual]
 

If the view is 1D compatible, should provide its 1D representation in n_elements and stride, and the returned pointer.

See Is1DCompatible(). Using the notation defined there, this function should:

  • place Size() in n_elements,
  • place K in stride,
  • return ptr

Implements dataview_interface< T >.

template<typename T>
T * matrixview< T >::Get2DRep itype n_series,
itype series_size,
itype series_extent
const [virtual]
 

If the view is 2D compatible, should provide its 2D representation in n_series, series_range, series_extent, and the returned pointer.

See Is2DCompatible(). Using the notation defined there, this function should:

  • place Range(0) in n_series,
  • place Range(1) in series_range,
  • return K in series_extent

Implements dataview_interface< T >.

template<class T>
virtual T& matrixview< T >::item itype  index  )  const [inline, virtual]
 

Should return a unique element corresponding to index, as long as index is in [0...Size()-1].

If the view has a 1DRep or 2DRep, then the ordering of the elements must agree with the ordering in that representation. Otherwise, there are no ordering requirements. Every element in the view must be accessible through this function, for some index in [0...Size()-1].

Implements dataview_interface< T >.

template<class T>
virtual T& matrixview< T >::element itype iarr  )  const [inline, virtual]
 

Should return a unique element corresponding to the set of indices iarr.

iarr must contain Dimensionality() indices, and iarr[i] must be in [0...Range(i)-1]. if Dimensionality() = 1, this function must agree with item( iarr[0] ). If the view has a 2DRep, the ordering must agree with it.

Implements dataview_interface< T >.

template<typename T>
T & matrixview< T >::element itype  i1,
  ...
const [virtual]
 

Should return a unique element corresponding to the first Dimensionality() parameters passed.

This function must behave identically to element( itype* iarr ) when Dimensionality() parameters are given. Extra parameters must be ignored. Behavior is undefined when insufficient parameters given.

Implements dataview_interface< T >.

template<typename T>
void matrixview< T >::PrettyPrint std::ostream &  os = std::cout  )  const [virtual]
 

Should print the elements of the view to os, formatted for human reading.

The exact format of printing is flexible -- it should be maximally readable for users.

Implements dataview_interface< T >.

template<typename T>
void matrixview< T >::DataPrint std::ostream &  os = std::cout  )  const [virtual]
 

Should print the elements of the view, arranged in columnar form, to os.

Unlike PrettyPrint(), DataPrint should follow a fairly strict format.

  • 1 dimensional views should be printed as "lines": sequences of numbers (of type T), separated by spaces. The numbers themselves should not contain spaces, or if they must, they should be enclosed in quotes.
  • 2 dimensional views should be printed as "blocks": sequences of "lines" (see above), separated by newline characters.
  • 3 dimensional views should be printed as a sequence of "blocks", separated by double newlines.
  • For 4 and higher dimensions, proceed recursively, separating N-dimensional "hyperblocks" by N newlines. Thus, e.g., a 4D view should be printed as a sequence of 3D views, separated by triple newlines.

Implements dataview_interface< T >.

template<class T>
virtual void matrixview< T >::OwnData bool  copyflag  )  [inline, virtual]
 

Ensures that the view has sole access to its datablock, by creating a virgin copy if necessary.

The purpose of OwnData() is to permit the view to ensure that it has sole control of the data that it references, possibly resizing it. Note that there is no way to tell who "owns" a block of data -- it is possible, although not explicitly supported through data_view, to identify how many views on a given datablock exist, but none of them have special "owner" rights. Thus, OwnData simply initializes new data and discards the old data. Note that the old data is copied only if copying is explicitly requested, since that can be slow. Also, it is permitted for a view to ignore this call IF-AND-ONLY-IF the reference count for its datablock is 1, meaning it already owns it.

Implements dataview_interface< T >.

template<typename T>
void matrixview< T >::FillFromStream std::istream &  is,
bool  clear = true
[virtual]
 

Should read in elements from a tabular data stream, and fill this view with them.

The FillFromStream() function is the input version of DataPrint(). It should read from a tabular data stream, where the format is simply T's separated by whitespace, with a newline for each end- of-series. Thus, a 2D dataset will have single newlines after each series, while a 3D dataset will have 2D blocks separated by double newlines. FillFromStream() maintains the current dimensions of the view, but replaces as much data as possible with that obtained from the stream. If clear = TRUE, then it will set all elements not specified by the stream to 0. See also InitFromStream().

Implements dataview_interface< T >.

template<typename T>
void matrixview< T >::InitFromStream std::istream &  is  )  [virtual]
 

Should reconstruct this view (changing size if necessary) to hold elements read in from a tabular data stream.

InitFromStream should read from a tabular data stream, where the format is simply T's separated by whitespace, with a newline for each end- of-series. Thus, a 2D dataset will have single newlines after each series, while a 3D dataset will have 2D blocks separated by double newlines. It then resizes the view to be just large enough to hold all that data, and fills it with the data read in. Elements not specified in the input stream will be set to zero. See also FillFromStream().

Implements dataview_interface< T >.


The documentation for this class was generated from the following file:
Generated on Wed Jun 14 22:25:28 2006 for linalg by  doxygen 1.4.4