From f0238cfb6997c4acfc2bd200de7295f3fa36968f Mon Sep 17 00:00:00 2001 From: Stanislaw Halik Date: Sun, 3 Mar 2019 21:09:10 +0100 Subject: don't index Eigen --- eigen/doc/TutorialBlockOperations.dox | 228 ---------------------------------- 1 file changed, 228 deletions(-) delete mode 100644 eigen/doc/TutorialBlockOperations.dox (limited to 'eigen/doc/TutorialBlockOperations.dox') diff --git a/eigen/doc/TutorialBlockOperations.dox b/eigen/doc/TutorialBlockOperations.dox deleted file mode 100644 index a2d8c97..0000000 --- a/eigen/doc/TutorialBlockOperations.dox +++ /dev/null @@ -1,228 +0,0 @@ -namespace Eigen { - -/** \eigenManualPage TutorialBlockOperations Block operations - -This page explains the essentials of block operations. -A block is a rectangular part of a matrix or array. Blocks expressions can be used both -as rvalues and as lvalues. As usual with Eigen expressions, this abstraction has zero runtime cost -provided that you let your compiler optimize. - -\eigenAutoToc - -\section TutorialBlockOperationsUsing Using block operations - -The most general block operation in Eigen is called \link DenseBase::block() .block() \endlink. -There are two versions, whose syntax is as follows: - - - - - - - - -
\b %Block \b operation -Version constructing a \n dynamic-size block expressionVersion constructing a \n fixed-size block expression
%Block of size (p,q), starting at (i,j)\code -matrix.block(i,j,p,q);\endcode \code -matrix.block(i,j);\endcode
- -As always in Eigen, indices start at 0. - -Both versions can be used on fixed-size and dynamic-size matrices and arrays. -These two expressions are semantically equivalent. -The only difference is that the fixed-size version will typically give you faster code if the block size is small, -but requires this size to be known at compile time. - -The following program uses the dynamic-size and fixed-size versions to print the values of several blocks inside a -matrix. - - - - -
Example:Output:
-\include Tutorial_BlockOperations_print_block.cpp - -\verbinclude Tutorial_BlockOperations_print_block.out -
- -In the above example the \link DenseBase::block() .block() \endlink function was employed as a \em rvalue, i.e. -it was only read from. However, blocks can also be used as \em lvalues, meaning that you can assign to a block. - -This is illustrated in the following example. This example also demonstrates blocks in arrays, which works exactly like the above-demonstrated blocks in matrices. - - - - -
Example:Output:
-\include Tutorial_BlockOperations_block_assignment.cpp - -\verbinclude Tutorial_BlockOperations_block_assignment.out -
- -While the \link DenseBase::block() .block() \endlink method can be used for any block operation, there are -other methods for special cases, providing more specialized API and/or better performance. On the topic of performance, all what -matters is that you give Eigen as much information as possible at compile time. For example, if your block is a single whole column in a matrix, -using the specialized \link DenseBase::col() .col() \endlink function described below lets Eigen know that, which can give it optimization opportunities. - -The rest of this page describes these specialized methods. - -\section TutorialBlockOperationsSyntaxColumnRows Columns and rows - -Individual columns and rows are special cases of blocks. Eigen provides methods to easily address them: -\link DenseBase::col() .col() \endlink and \link DenseBase::row() .row()\endlink. - - - - - - - - - - -
%Block operationMethod
ith row - \link DenseBase::row() * \endlink\code -matrix.row(i);\endcode
jth column - \link DenseBase::col() * \endlink\code -matrix.col(j);\endcode
- -The argument for \p col() and \p row() is the index of the column or row to be accessed. As always in Eigen, indices start at 0. - - - - -
Example:Output:
-\include Tutorial_BlockOperations_colrow.cpp - -\verbinclude Tutorial_BlockOperations_colrow.out -
- -That example also demonstrates that block expressions (here columns) can be used in arithmetic like any other expression. - - -\section TutorialBlockOperationsSyntaxCorners Corner-related operations - -Eigen also provides special methods for blocks that are flushed against one of the corners or sides of a -matrix or array. For instance, \link DenseBase::topLeftCorner() .topLeftCorner() \endlink can be used to refer -to a block in the top-left corner of a matrix. - -The different possibilities are summarized in the following table: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
%Block \b operation -Version constructing a \n dynamic-size block expressionVersion constructing a \n fixed-size block expression
Top-left p by q block \link DenseBase::topLeftCorner() * \endlink\code -matrix.topLeftCorner(p,q);\endcode \code -matrix.topLeftCorner();\endcode
Bottom-left p by q block - \link DenseBase::bottomLeftCorner() * \endlink\code -matrix.bottomLeftCorner(p,q);\endcode \code -matrix.bottomLeftCorner();\endcode
Top-right p by q block - \link DenseBase::topRightCorner() * \endlink\code -matrix.topRightCorner(p,q);\endcode \code -matrix.topRightCorner();\endcode
Bottom-right p by q block - \link DenseBase::bottomRightCorner() * \endlink\code -matrix.bottomRightCorner(p,q);\endcode \code -matrix.bottomRightCorner();\endcode
%Block containing the first q rows - \link DenseBase::topRows() * \endlink\code -matrix.topRows(q);\endcode \code -matrix.topRows();\endcode
%Block containing the last q rows - \link DenseBase::bottomRows() * \endlink\code -matrix.bottomRows(q);\endcode \code -matrix.bottomRows();\endcode
%Block containing the first p columns - \link DenseBase::leftCols() * \endlink\code -matrix.leftCols(p);\endcode \code -matrix.leftCols

();\endcode

%Block containing the last q columns - \link DenseBase::rightCols() * \endlink\code -matrix.rightCols(q);\endcode \code -matrix.rightCols();\endcode
- -Here is a simple example illustrating the use of the operations presented above: - - - - -
Example:Output:
-\include Tutorial_BlockOperations_corner.cpp - -\verbinclude Tutorial_BlockOperations_corner.out -
- - -\section TutorialBlockOperationsSyntaxVectors Block operations for vectors - -Eigen also provides a set of block operations designed specifically for the special case of vectors and one-dimensional arrays: - - - - - - - - - - - - - - - - - -
%Block operationVersion constructing a \n dynamic-size block expressionVersion constructing a \n fixed-size block expression
%Block containing the first \p n elements - \link DenseBase::head() * \endlink\code -vector.head(n);\endcode \code -vector.head();\endcode
%Block containing the last \p n elements - \link DenseBase::tail() * \endlink\code -vector.tail(n);\endcode \code -vector.tail();\endcode
%Block containing \p n elements, starting at position \p i - \link DenseBase::segment() * \endlink\code -vector.segment(i,n);\endcode \code -vector.segment(i);\endcode
- - -An example is presented below: - - - -
Example:Output:
-\include Tutorial_BlockOperations_vector.cpp - -\verbinclude Tutorial_BlockOperations_vector.out -
- -*/ - -} -- cgit v1.2.3