# Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > Class Template Reference

The matrix class, also used for vectors and row-vectors. More...

`#include <Matrix.h>`

Inheritance diagram for Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >:

List of all members.

## Public Types

enum  { Options = _Options }
enum  { NeedsToAlign }
typedef PlainObjectBase< MatrixBase
Base class typedef.
typedef Base::PlainObject PlainObject

## Public Member Functions

EIGEN_STRONG_INLINE Matrixoperator= (const Matrix &other)
Assigns matrices to each other.
template<typename OtherDerived >
EIGEN_STRONG_INLINE Matrixoperator= (const MatrixBase< OtherDerived > &other)
template<typename OtherDerived >
EIGEN_STRONG_INLINE Matrixoperator= (const EigenBase< OtherDerived > &other)
Copies the generic expression other into *this.
template<typename OtherDerived >
EIGEN_STRONG_INLINE Matrixoperator= (const ReturnByValue< OtherDerived > &func)
EIGEN_STRONG_INLINE Matrix ()
Default constructor.
Matrix (internal::constructor_without_unaligned_array_assert)
EIGEN_STRONG_INLINE Matrix (Index dim)
Constructs a vector or row-vector with given dimension. .
template<typename T0 , typename T1 >
EIGEN_STRONG_INLINE Matrix (const T0 &x, const T1 &y)
EIGEN_STRONG_INLINE Matrix (const Scalar &x, const Scalar &y, const Scalar &z)
Constructs an initialized 3D vector with given coefficients.
EIGEN_STRONG_INLINE Matrix (const Scalar &x, const Scalar &y, const Scalar &z, const Scalar &w)
Constructs an initialized 4D vector with given coefficients.
Matrix (const Scalar *data)
template<typename OtherDerived >
EIGEN_STRONG_INLINE Matrix (const MatrixBase< OtherDerived > &other)
Constructor copying the value of the expression other.
EIGEN_STRONG_INLINE Matrix (const Matrix &other)
Copy constructor.
template<typename OtherDerived >
EIGEN_STRONG_INLINE Matrix (const ReturnByValue< OtherDerived > &other)
Copy constructor with in-place evaluation.
template<typename OtherDerived >
EIGEN_STRONG_INLINE Matrix (const EigenBase< OtherDerived > &other)
Copy constructor for generic expressions.
template<typename OtherDerived >
void swap (MatrixBase< OtherDerived > const &other)
Index innerStride () const
Index outerStride () const
template<typename OtherDerived >
Matrix (const RotationBase< OtherDerived, ColsAtCompileTime > &r)
Constructs a Dim x Dim rotation matrix from the rotation r.
template<typename OtherDerived >
Matrixoperator= (const RotationBase< OtherDerived, ColsAtCompileTime > &r)
Set a Dim x Dim rotation matrix from the rotation r.

## Friends

struct internal::conservative_resize_like_impl

## Detailed Description

### template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols> class Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >

The matrix class, also used for vectors and row-vectors.

The Matrix class is the work-horse for all dense (note) matrices and vectors within Eigen. Vectors are matrices with one column, and row-vectors are matrices with one row.

The Matrix class encompasses both fixed-size and dynamic-size objects (note).

The first three template parameters are required:

Template Parameters:
 _Scalar Numeric type, e.g. float, double, int or std::complex. User defined sclar types are supported as well (see here). _Rows Number of rows, or Dynamic _Cols Number of columns, or Dynamic

The remaining template parameters are optional -- in most cases you don't have to worry about them.

Template Parameters:
 _Options A combination of either RowMajor or ColMajor, and of either AutoAlign or DontAlign. The former controls storage order, and defaults to column-major. The latter controls alignment, which is required for vectorization. It defaults to aligning matrices except for fixed sizes that aren't a multiple of the packet size. _MaxRows Maximum number of rows. Defaults to _Rows (note). _MaxCols Maximum number of columns. Defaults to _Cols (note).

Eigen provides a number of typedefs covering the usual cases. Here are some examples:

• `Matrix2d` is a 2x2 square matrix of doubles (`Matrix<double, 2, 2>`)
• `Vector4f` is a vector of 4 floats (`Matrix<float, 4, 1>`)
• `RowVector3i` is a row-vector of 3 ints (`Matrix<int, 1, 3>`)
• `MatrixXf` is a dynamic-size matrix of floats (`Matrix<float, Dynamic, Dynamic>`)
• `VectorXf` is a dynamic-size vector of floats (`Matrix<float, Dynamic, 1>`)
• `Matrix2Xf` is a partially fixed-size (dynamic-size) matrix of floats (`Matrix<float, 2, Dynamic>`)
• `MatrixX3d` is a partially dynamic-size (fixed-size) matrix of double (`Matrix<double, Dynamic, 3>`)

See this page for a complete list of predefined Matrix and Vector typedefs.

You can access elements of vectors and matrices using normal subscripting:

``` Eigen::VectorXd v(10);
v[0] = 0.1;
v[1] = 0.2;
v(0) = 0.3;
v(1) = 0.4;

Eigen::MatrixXi m(10, 10);
m(0, 1) = 1;
m(0, 2) = 2;
m(0, 3) = 3;
```

This class can be extended with the help of the plugin mechanism described on the page TopicCustomizingEigen by defining the preprocessor symbol `EIGEN_MATRIX_PLUGIN`.

Some notes:

Dense versus sparse:

This Matrix class handles dense, not sparse matrices and vectors. For sparse matrices and vectors, see the Sparse module.

Dense matrices and vectors are plain usual arrays of coefficients. All the coefficients are stored, in an ordinary contiguous array. This is unlike Sparse matrices and vectors where the coefficients are stored as a list of nonzero coefficients.

Fixed-size versus dynamic-size:

Fixed-size means that the numbers of rows and columns are known are compile-time. In this case, Eigen allocates the array of coefficients as a fixed-size array, as a class member. This makes sense for very small matrices, typically up to 4x4, sometimes up to 16x16. Larger matrices should be declared as dynamic-size even if one happens to know their size at compile-time.

Dynamic-size means that the numbers of rows or columns are not necessarily known at compile-time. In this case they are runtime variables, and the array of coefficients is allocated dynamically on the heap.

Note that dense matrices, be they Fixed-size or Dynamic-size, do not expand dynamically in the sense of a std::map. If you want this behavior, see the Sparse module.

_MaxRows and _MaxCols:
In most cases, one just leaves these parameters to the default values. These parameters mean the maximum size of rows and columns that the matrix may have. They are useful in cases when the exact numbers of rows and columns are not known are compile-time, but it is known at compile-time that they cannot exceed a certain value. This happens when taking dynamic-size blocks inside fixed-size matrices: in this case _MaxRows and _MaxCols are the dimensions of the original matrix, while _Rows and _Cols are Dynamic.
MatrixBase for the majority of the API methods for matrices, TopicClassHierarchy, TopicStorageOrders

## Member Typedef Documentation

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 typedef PlainObjectBase Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Base

Base class typedef.

PlainObjectBase
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 typedef Base::PlainObject Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::PlainObject

## Member Enumeration Documentation

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 anonymous enum
Enumerator:
 Options
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 anonymous enum
Enumerator:
 NeedsToAlign

## Constructor & Destructor Documentation

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( ) ` [inline, explicit]`

Default constructor.

For fixed-size matrices, does nothing.

For dynamic-size matrices, creates an empty matrix of size 0. Does not allocate any array. Such a matrix is called a null matrix. This constructor is the unique way to create null matrices: resizing a matrix to 0 is not supported.

resize(Index,Index)
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( internal::constructor_without_unaligned_array_assert ) ` [inline]`
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( Index dim ) ` [inline, explicit]`

Constructs a vector or row-vector with given dimension. .

Note that this is only useful for dynamic-size vectors. For fixed-size vectors, it is redundant to pass the dimension here, so it makes more sense to use the default constructor Matrix() instead.

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
template<typename T0 , typename T1 >
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( const T0 & x, const T1 & y ) ` [inline]`
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( const Scalar & x, const Scalar & y, const Scalar & z ) ` [inline]`

Constructs an initialized 3D vector with given coefficients.

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( const Scalar & x, const Scalar & y, const Scalar & z, const Scalar & w ) ` [inline]`

Constructs an initialized 4D vector with given coefficients.

template<typename _Scalar , int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( const Scalar * data ) ` [inline, explicit]`
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( const MatrixBase< OtherDerived > & other ) ` [inline]`

Constructor copying the value of the expression other.

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( const Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & other ) ` [inline]`

Copy constructor.

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( const ReturnByValue< OtherDerived > & other ) ` [inline]`

Copy constructor with in-place evaluation.

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 EIGEN_STRONG_INLINE Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::Matrix ( const EigenBase< OtherDerived > & other ) ` [inline]`

Copy constructor for generic expressions.

MatrixBase::operator=(const EigenBase<OtherDerived>&)
template<typename _Scalar , int _Rows, int _Cols, int _Storage, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 Matrix< _Scalar, _Rows, _Cols, _Storage, _MaxRows, _MaxCols >::Matrix ( const RotationBase< OtherDerived, ColsAtCompileTime > & r ) ` [explicit]`

Constructs a Dim x Dim rotation matrix from the rotation r.

Constructs a Dim x Dim rotation matrix from the rotation r

## Member Function Documentation

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 Index Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::innerStride ( ) const` [inline]`
template<typename _Scalar , int _Rows, int _Cols, int _Storage, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 Matrix< _Scalar, _Rows, _Cols, _Storage, _MaxRows, _MaxCols > & Matrix< _Scalar, _Rows, _Cols, _Storage, _MaxRows, _MaxCols >::operator= ( const RotationBase< OtherDerived, ColsAtCompileTime > & r )

Set a Dim x Dim rotation matrix from the rotation r.

Set a Dim x Dim rotation matrix from the rotation r

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 EIGEN_STRONG_INLINE Matrix& Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::operator= ( const MatrixBase< OtherDerived > & other ) ` [inline]`
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 EIGEN_STRONG_INLINE Matrix& Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::operator= ( const EigenBase< OtherDerived > & other ) ` [inline]`

Copies the generic expression other into *this.

The expression must provide a (templated) evalTo(Derived& dst) const function which does the actual job. In practice, this allows any user to write its own special matrix without having to modify MatrixBase

Returns:
a reference to *this.
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 EIGEN_STRONG_INLINE Matrix& Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::operator= ( const ReturnByValue< OtherDerived > & func ) ` [inline]`
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 EIGEN_STRONG_INLINE Matrix& Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::operator= ( const Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & other ) ` [inline]`

Assigns matrices to each other.

Note:
This is a special case of the templated operator=. Its purpose is to prevent a default operator= from hiding the templated operator=.
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 Index Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::outerStride ( ) const` [inline]`
template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
template<typename OtherDerived >
 void Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols >::swap ( MatrixBase< OtherDerived > const & other ) ` [inline]`

## Friends And Related Function Documentation

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
 friend struct internal::conservative_resize_like_impl` [friend]`

The documentation for this class was generated from the following files:
• /home/hauberg/Dokumenter/Capture/humim-tracker-0.1/src/ntk/geometry/Eigen/src/Core/Matrix.h
• /home/hauberg/Dokumenter/Capture/humim-tracker-0.1/src/ntk/geometry/Eigen/src/Core/Map.h
• /home/hauberg/Dokumenter/Capture/humim-tracker-0.1/src/ntk/geometry/Eigen/src/Eigen2Support/Geometry/RotationBase.h
• /home/hauberg/Dokumenter/Capture/humim-tracker-0.1/src/ntk/geometry/Eigen/src/Geometry/RotationBase.h