Public Types | Public Member Functions | Protected Attributes | List of all members
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > Class Template Reference

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

Public Types

enum  { Options }
enum  { NeedsToAlign }
typedef class Eigen::Map
< Matrix, Aligned > 
AlignedMapType
typedef class Eigen::Map
< Matrix, Unaligned > 
UnalignedMapType
- Public Types inherited from MatrixBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >
enum  

Public Member Functions

Base & base ()
const Base & base () const
const Scalar & coeff (int row, int col) const
const Scalar & coeff (int index) const
Scalar & coeffRef (int row, int col)
Scalar & coeffRef (int index)
int cols () const
const Scalar * data () const
Scalar * data ()
 Matrix ()
 Matrix (int dim)
 Matrix (int x, int y)
 Matrix (const float &x, const float &y)
 Matrix (const double &x, const double &y)
 Matrix (const Scalar &x, const Scalar &y, const Scalar &z)
 Matrix (const Scalar &x, const Scalar &y, const Scalar &z, const Scalar &w)
 Matrix (const Scalar *data)
template<typename OtherDerived >
 Matrix (const MatrixBase< OtherDerived > &other)
 Matrix (const Matrix &other)
template<typename OtherDerived >
 Matrix (const RotationBase< OtherDerived, ColsAtCompileTime > &r)
template<typename OtherDerived >
Matrixoperator= (const MatrixBase< OtherDerived > &other)
Matrixoperator= (const Matrix &other)
template<typename OtherDerived >
Matrixoperator= (const RotationBase< OtherDerived, ColsAtCompileTime > &r)
template<int LoadMode>
PacketScalar packet (int row, int col) const
template<int LoadMode>
PacketScalar packet (int index) const
void resize (int rows, int cols)
void resize (int size)
int rows () const
MatrixsetConstant (int size, const Scalar &value)
MatrixsetConstant (int rows, int cols, const Scalar &value)
MatrixsetIdentity (int rows, int cols)
MatrixsetOnes (int size)
MatrixsetOnes (int rows, int cols)
MatrixsetRandom (int size)
MatrixsetRandom (int rows, int cols)
MatrixsetZero (int size)
MatrixsetZero (int rows, int cols)
int stride (void) const
template<typename OtherDerived >
void swap (const MatrixBase< OtherDerived > &other)
template<int StoreMode>
void writePacket (int row, int col, const PacketScalar &x)
template<int StoreMode>
void writePacket (int index, const PacketScalar &x)
 ~Matrix ()
- Public Member Functions inherited from MatrixBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >
const AdjointReturnType adjoint () const
bool all (void) const
bool any (void) const
const DiagonalMatrix< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
asDiagonal () const
const CwiseBinaryOp
< CustomBinaryOp, Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, OtherDerived > 
binaryExpr (const MatrixBase< OtherDerived > &other, const CustomBinaryOp &func=CustomBinaryOp()) const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::Type 
block (int startRow, int startCol, int blockRows, int blockCols)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::Type 
block (int startRow, int startCol, int blockRows, int blockCols) const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, BlockRows, BlockCols >::Type 
block (int startRow, int startCol)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, BlockRows, BlockCols >::Type 
block (int startRow, int startCol) const
const CwiseUnaryOp
< ei_scalar_cast_op< typename
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar,
NewType >, Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > > 
cast () const
ColXpr col (int i)
const ColXpr col (int i) const
const PartialRedux< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Vertical > 
colwise () const
void computeInverse (MatrixBase< ResultType > *result) const
ConjugateReturnType conjugate () const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::Type 
corner (CornerType type, int cRows, int cCols)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::Type 
corner (CornerType type, int cRows, int cCols) const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, CRows, CCols >::Type 
corner (CornerType type)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, CRows, CCols >::Type 
corner (CornerType type) const
int count () const
PlainMatrixType cross (const MatrixBase< OtherDerived > &other) const
const Cwise< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > > 
cwise () const
Cwise< Matrix< _Scalar, _Rows,
_Cols, _Options, _MaxRows,
_MaxCols > > 
cwise ()
Scalar determinant () const
DiagonalCoeffs< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
diagonal ()
const DiagonalCoeffs< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
diagonal () const
Scalar dot (const MatrixBase< OtherDerived > &other) const
EigenvaluesReturnType eigenvalues () const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Dynamic >::SubVectorType 
end (int size)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Dynamic >::SubVectorType 
end (int size) const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Size >::SubVectorType 
end ()
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Size >::SubVectorType 
end () const
Matrix< Scalar, 3, 1 > eulerAngles (int a0, int a1, int a2) const
const ei_eval< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::type 
eval () const
void fill (const Scalar &value)
const WithFormat< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
format (const IOFormat &fmt) const
const ImagReturnType imag () const
int innerSize () const
const PlainMatrixType inverse () const
bool isApprox (const MatrixBase< OtherDerived > &other, RealScalar prec=precision< Scalar >()) const
bool isApproxToConstant (const Scalar &value, RealScalar prec=precision< Scalar >()) const
bool isConstant (const Scalar &value, RealScalar prec=precision< Scalar >()) const
bool isDiagonal (RealScalar prec=precision< Scalar >()) const
bool isIdentity (RealScalar prec=precision< Scalar >()) const
bool isLowerTriangular (RealScalar prec=precision< Scalar >()) const
bool isMuchSmallerThan (const RealScalar &other, RealScalar prec=precision< Scalar >()) const
bool isMuchSmallerThan (const MatrixBase< OtherDerived > &other, RealScalar prec=precision< Scalar >()) const
bool isOnes (RealScalar prec=precision< Scalar >()) const
bool isOrthogonal (const MatrixBase< OtherDerived > &other, RealScalar prec=precision< Scalar >()) const
bool isUnitary (RealScalar prec=precision< Scalar >()) const
bool isUpperTriangular (RealScalar prec=precision< Scalar >()) const
bool isVector () const
bool isZero (RealScalar prec=precision< Scalar >()) const
const Flagged< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols >
, 0, EvalBeforeNestingBit|EvalBeforeAssigningBit > 
lazy () const
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
lazyAssign (const SparseProduct< Derived1, Derived2, SparseTimeDenseProduct > &product)
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
lazyAssign (const SparseProduct< Derived1, Derived2, DenseTimeSparseProduct > &product)
const LDLT< PlainMatrixType > ldlt () const
const LLT< PlainMatrixType > llt () const
RealScalar lpNorm () const
const LU< PlainMatrixType > lu () const
const Flagged< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols >, Added, 0 > 
marked () const
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar 
maxCoeff () const
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar 
maxCoeff (int *row, int *col) const
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar 
maxCoeff (int *index) const
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar 
minCoeff () const
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar 
minCoeff (int *row, int *col) const
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar 
minCoeff (int *index) const
Minor< Matrix< _Scalar, _Rows,
_Cols, _Options, _MaxRows,
_MaxCols > > 
minor (int row, int col)
const Minor< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > > 
minor (int row, int col) const
const NestByValue< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
nestByValue () const
int nonZeros () const
RealScalar norm () const
void normalize ()
const PlainMatrixType normalized () const
bool operator!= (const MatrixBase< OtherDerived > &other) const
const Scalar operator() (int row, int col) const
Scalar & operator() (int row, int col)
const Scalar operator() (int index) const
Scalar & operator() (int index)
const ScalarMultipleReturnType operator* (const Scalar &scalar) const
const ProductReturnType
< Matrix< _Scalar, _Rows,
_Cols, _Options, _MaxRows,
_MaxCols >, OtherDerived >
::Type 
operator* (const MatrixBase< OtherDerived > &other) const
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
operator*= (const Scalar &other)
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
operator*= (const MatrixBase< OtherDerived > &other)
const CwiseBinaryOp
< ei_scalar_sum_op< typename
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar >
, Matrix< _Scalar, _Rows,
_Cols, _Options, _MaxRows,
_MaxCols >, OtherDerived > 
operator+ (const MatrixBase< OtherDerived > &other) const
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
operator+= (const MatrixBase< OtherDerived > &other)
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
operator+= (const Flagged< Product< Lhs, Rhs, CacheFriendlyProduct >, 0, EvalBeforeNestingBit|EvalBeforeAssigningBit > &other)
const CwiseUnaryOp
< ei_scalar_opposite_op
< typename ei_traits< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::Scalar >, Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > > 
operator- () const
const CwiseBinaryOp
< ei_scalar_difference_op
< typename ei_traits< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::Scalar >, Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols >
, OtherDerived > 
operator- (const MatrixBase< OtherDerived > &other) const
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
operator-= (const MatrixBase< OtherDerived > &other)
const CwiseUnaryOp
< ei_scalar_quotient1_op
< typename ei_traits< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::Scalar >, Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > > 
operator/ (const Scalar &scalar) const
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
operator/= (const Scalar &other)
CommaInitializer< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
operator<< (const Scalar &s)
CommaInitializer< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
operator<< (const MatrixBase< OtherDerived > &other)
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
operator= (const MatrixBase &other)
bool operator== (const MatrixBase< OtherDerived > &other) const
const Scalar operator[] (int index) const
Scalar & operator[] (int index)
RealScalar operatorNorm () const
int outerSize () const
Part< Matrix< _Scalar, _Rows,
_Cols, _Options, _MaxRows,
_MaxCols >, Mode > 
part ()
const Part< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols >, Mode > 
part () const
const QR< PlainMatrixType > qr () const
const RealReturnType real () const
ei_result_of< BinaryOp(typename
ei_traits< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols > >::Scalar)>
::type 
redux (const BinaryOp &func) const
RowXpr row (int i)
const RowXpr row (int i) const
const PartialRedux< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Horizontal > 
rowwise () const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::SubVectorType 
segment (int start, int size)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
>::SubVectorType 
segment (int start, int size) const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Size >::SubVectorType 
segment (int start)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Size >::SubVectorType 
segment (int start) const
const Select< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols >
, ThenDerived, ElseDerived > 
select (const MatrixBase< ThenDerived > &thenMatrix, const MatrixBase< ElseDerived > &elseMatrix) const
const Select< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols >
, ThenDerived, NestByValue
< typename
ThenDerived::ConstantReturnType > > 
select (const MatrixBase< ThenDerived > &thenMatrix, typename ThenDerived::Scalar elseScalar) const
const Select< Matrix< _Scalar,
_Rows, _Cols, _Options,
_MaxRows, _MaxCols >
, NestByValue< typename
ElseDerived::ConstantReturnType >
, ElseDerived > 
select (typename ElseDerived::Scalar thenScalar, const MatrixBase< ElseDerived > &elseMatrix) const
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
setConstant (const Scalar &value)
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
setIdentity ()
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
setOnes ()
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
setRandom ()
Matrix< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > & 
setZero ()
int size () const
ei_plain_matrix_type_column_major
< OtherDerived >::type 
solveTriangular (const MatrixBase< OtherDerived > &other) const
void solveTriangularInPlace (const MatrixBase< OtherDerived > &other) const
RealScalar squaredNorm () const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Dynamic >::SubVectorType 
start (int size)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Dynamic >::SubVectorType 
start (int size) const
BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Size >::SubVectorType 
start (void)
const BlockReturnType< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols >
, Size >::SubVectorType 
start () const
Scalar sum () const
SVD< PlainMatrixType > svd () const
Scalar trace () const
Eigen::Transpose< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
transpose ()
const Eigen::Transpose< Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
transpose () const
void transposeInPlace ()
const CwiseUnaryOp
< CustomUnaryOp, Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
unaryExpr (const CustomUnaryOp &func=CustomUnaryOp()) const
PlainMatrixType unitOrthogonal (void) const
void visit (Visitor &func) const
const Scalar w () const
Scalar & w ()
const Scalar x () const
Scalar & x ()
const Scalar y () const
Scalar & y ()
const Scalar z () const
Scalar & z ()

Static Public Member Functions

Map

These are convenience functions returning Map objects.

Warning
Do not use MapAligned in the Eigen 2.0. Mapping aligned arrays will be fully supported in Eigen 3.0 (already implemented in the development branch)
See Also
class Map
static const UnalignedMapType Map (const Scalar *data)
static UnalignedMapType Map (Scalar *data)
static const UnalignedMapType Map (const Scalar *data, int size)
static UnalignedMapType Map (Scalar *data, int size)
static const UnalignedMapType Map (const Scalar *data, int rows, int cols)
static UnalignedMapType Map (Scalar *data, int rows, int cols)
static const AlignedMapType MapAligned (const Scalar *data)
static AlignedMapType MapAligned (Scalar *data)
static const AlignedMapType MapAligned (const Scalar *data, int size)
static AlignedMapType MapAligned (Scalar *data, int size)
static const AlignedMapType MapAligned (const Scalar *data, int rows, int cols)
static AlignedMapType MapAligned (Scalar *data, int rows, int cols)
- Static Public Member Functions inherited from MatrixBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >
static const ConstantReturnType Constant (int rows, int cols, const Scalar &value)
static const ConstantReturnType Constant (int size, const Scalar &value)
static const ConstantReturnType Constant (const Scalar &value)
static const IdentityReturnType Identity ()
static const IdentityReturnType Identity (int rows, int cols)
static const CwiseNullaryOp
< CustomNullaryOp, Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
NullaryExpr (int rows, int cols, const CustomNullaryOp &func)
static const CwiseNullaryOp
< CustomNullaryOp, Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
NullaryExpr (int size, const CustomNullaryOp &func)
static const CwiseNullaryOp
< CustomNullaryOp, Matrix
< _Scalar, _Rows, _Cols,
_Options, _MaxRows, _MaxCols > > 
NullaryExpr (const CustomNullaryOp &func)
static const ConstantReturnType Ones (int rows, int cols)
static const ConstantReturnType Ones (int size)
static const ConstantReturnType Ones ()
static const CwiseNullaryOp
< ei_scalar_random_op< Scalar >
, Matrix< _Scalar, _Rows,
_Cols, _Options, _MaxRows,
_MaxCols > > 
Random (int rows, int cols)
static const CwiseNullaryOp
< ei_scalar_random_op< Scalar >
, Matrix< _Scalar, _Rows,
_Cols, _Options, _MaxRows,
_MaxCols > > 
Random (int size)
static const CwiseNullaryOp
< ei_scalar_random_op< Scalar >
, Matrix< _Scalar, _Rows,
_Cols, _Options, _MaxRows,
_MaxCols > > 
Random ()
static const BasisReturnType Unit (int size, int i)
static const BasisReturnType Unit (int i)
static const BasisReturnType UnitW ()
static const BasisReturnType UnitX ()
static const BasisReturnType UnitY ()
static const BasisReturnType UnitZ ()
static const ConstantReturnType Zero (int rows, int cols)
static const ConstantReturnType Zero (int size)
static const ConstantReturnType Zero ()

Protected Attributes

ei_matrix_storage< Scalar,
MaxSizeAtCompileTime,
RowsAtCompileTime,
ColsAtCompileTime, Options > 
m_storage

Additional Inherited Members

- Protected Member Functions inherited from MatrixBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >
 MatrixBase ()

Detailed Description

template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols>
class Eigen::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:

Parameters
_ScalarNumeric type, i.e. float, double, int
_RowsNumber of rows, or Dynamic
_ColsNumber of columns, or Dynamic

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

Parameters
_OptionsA 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.
_MaxRowsMaximum number of rows. Defaults to _Rows (note).
_MaxColsMaximum number of columns. Defaults to _Cols (note).

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

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

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

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;

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.
See Also
MatrixBase for the majority of the API methods for matrices

Constructor & Destructor Documentation

Matrix ( )
inlineexplicit

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.

See Also
resize(int,int)
Matrix ( int  dim)
inlineexplicit

Constructs a vector or row-vector with given dimension. This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

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.

Matrix ( int  x,
int  y 
)
inline

This constructor has two very different behaviors, depending on the type of *this.

  • When Matrix is a fixed-size vector type of size 2, this constructor constructs an initialized vector. The parameters x, y are copied into the first and second coords of the vector respectively.
  • Otherwise, this constructor constructs an uninitialized matrix with x rows and y columns. This is useful for dynamic-size matrices. For fixed-size matrices, it is redundant to pass these parameters, so one should use the default constructor Matrix() instead.
Matrix ( const float &  x,
const float &  y 
)
inline

constructs an initialized 2D vector with given coefficients

Matrix ( const double &  x,
const double &  y 
)
inline

constructs an initialized 2D vector with given coefficients

Matrix ( const Scalar &  x,
const Scalar &  y,
const Scalar &  z 
)
inline

constructs an initialized 3D vector with given coefficients

Matrix ( const Scalar &  x,
const Scalar &  y,
const Scalar &  z,
const Scalar &  w 
)
inline

constructs an initialized 4D vector with given coefficients

Matrix ( const Scalar *  data)
inlineexplicit

Constructor copying an existing array of data. Only for fixed-size matrices and vectors.

Parameters
dataThe array of data to copy
See Also
Matrix::Map(const Scalar *)
Matrix ( const MatrixBase< OtherDerived > &  other)
inline

Constructor copying the value of the expression other

Matrix ( const Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > &  other)
inline

Copy constructor

~Matrix ( )
inline

Destructor

Matrix ( const RotationBase< OtherDerived, ColsAtCompileTime > &  r)
explicit

This is defined in the Geometry module.

#include <Eigen/Geometry>

Constructs a Dim x Dim rotation matrix from the rotation r

Member Function Documentation

int cols ( void  ) const
inline
const Scalar* data ( ) const
inline
Returns
a const pointer to the data array of this matrix
Scalar* data ( )
inline
Returns
a pointer to the data array of this matrix
Matrix& operator= ( const MatrixBase< OtherDerived > &  other)
inline

Copies the value of the expression other into *this with automatic resizing.

*this might be resized to match the dimensions of other. If *this was a null matrix (not already initialized), it will be initialized.

Note that copying a row-vector into a vector (and conversely) is allowed. The resizing, if any, is then done in the appropriate way so that row-vectors remain row-vectors and vectors remain vectors.

Reimplemented from MatrixBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >.

Matrix& operator= ( const Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > &  other)
inline

This is a special case of the templated operator=. Its purpose is to prevent a default operator= from hiding the templated operator=.

Matrix< _Scalar, _Rows, _Cols, _Storage, _MaxRows, _MaxCols > & operator= ( const RotationBase< OtherDerived, ColsAtCompileTime > &  r)

This is defined in the Geometry module.

#include <Eigen/Geometry>

Set a Dim x Dim rotation matrix from the rotation r

void resize ( int  rows,
int  cols 
)
inline

Resizes *this to a rows x cols matrix.

Makes sense for dynamic-size matrices only.

If the current number of coefficients of *this exactly matches the product rows * cols, then no memory allocation is performed and the current values are left unchanged. In all other cases, including shrinking, the data is reallocated and all previous values are lost.

See Also
resize(int) for vectors.
void resize ( int  size)
inline

Resizes *this to a vector of length size

See Also
resize(int,int) for the details.
int rows ( void  ) const
inline
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setConstant ( int  size,
const Scalar &  value 
)
inline

Resizes to the given size, and sets all coefficients in this expression to the given value.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Example:

Output:

See Also
MatrixBase::setConstant(const Scalar&), setConstant(int,int,const Scalar&), class CwiseNullaryOp, MatrixBase::Constant(const Scalar&)
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setConstant ( int  rows,
int  cols,
const Scalar &  value 
)
inline

Resizes to the given size, and sets all coefficients in this expression to the given value.

Parameters
rowsthe new number of rows
colsthe new number of columns

Example:

Output:

See Also
MatrixBase::setConstant(const Scalar&), setConstant(int,const Scalar&), class CwiseNullaryOp, MatrixBase::Constant(const Scalar&)
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setIdentity ( int  rows,
int  cols 
)
inline

Resizes to the given size, and writes the identity expression (not necessarily square) into *this.

Parameters
rowsthe new number of rows
colsthe new number of columns

Example:

Output:

See Also
MatrixBase::setIdentity(), class CwiseNullaryOp, MatrixBase::Identity()
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setOnes ( int  size)
inline

Resizes to the given size, and sets all coefficients in this expression to one.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Example:

Output:

See Also
MatrixBase::setOnes(), setOnes(int,int), class CwiseNullaryOp, MatrixBase::Ones()
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setOnes ( int  rows,
int  cols 
)
inline

Resizes to the given size, and sets all coefficients in this expression to one.

Parameters
rowsthe new number of rows
colsthe new number of columns

Example:

Output:

See Also
MatrixBase::setOnes(), setOnes(int), class CwiseNullaryOp, MatrixBase::Ones()
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setRandom ( int  size)
inline

Resizes to the given size, and sets all coefficients in this expression to random values.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Example:

Output:

See Also
MatrixBase::setRandom(), setRandom(int,int), class CwiseNullaryOp, MatrixBase::Random()
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setRandom ( int  rows,
int  cols 
)
inline

Resizes to the given size, and sets all coefficients in this expression to random values.

Parameters
rowsthe new number of rows
colsthe new number of columns

Example:

Output:

See Also
MatrixBase::setRandom(), setRandom(int), class CwiseNullaryOp, MatrixBase::Random()
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setZero ( int  size)
inline

Resizes to the given size, and sets all coefficients in this expression to zero.

This is only for vectors (either row-vectors or column-vectors), i.e. matrices which are known at compile-time to have either one row or one column.

Example:

Output:

See Also
MatrixBase::setZero(), setZero(int,int), class CwiseNullaryOp, MatrixBase::Zero()
Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > & setZero ( int  rows,
int  cols 
)
inline

Resizes to the given size, and sets all coefficients in this expression to zero.

Parameters
rowsthe new number of rows
colsthe new number of columns

Example:

Output:

See Also
MatrixBase::setZero(), setZero(int), class CwiseNullaryOp, MatrixBase::Zero()
int stride ( void  ) const
inline
Returns
number of elements to skip to pass from one row (resp. column) to another for a row-major (resp. column-major) matrix. Combined with coeffRef() and the flags flags, it allows a direct access to the data of the underlying matrix.

Reimplemented from MatrixBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >.

void swap ( const MatrixBase< OtherDerived > &  other)
inline

Override MatrixBase::swap() since for dynamic-sized matrices of same type it is enough to swap the data pointers.

Reimplemented from MatrixBase< Matrix< _Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols > >.


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