// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008-2009 Gael Guennebaud
// Copyright (C) 2007-2009 Benoit Jacob
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
#ifndef EIGEN_CONSTANTS_H
#define EIGEN_CONSTANTS_H
namespace Eigen {
/** This value means that a positive quantity (e.g., a size) is not known at compile-time, and that instead the value is
* stored in some runtime variable.
*
* Changing the value of Dynamic breaks the ABI, as Dynamic is often used as a template parameter for Matrix.
*/
const int Dynamic = -1;
/** This value means that a signed quantity (e.g., a signed index) is not known at compile-time, and that instead its value
* has to be specified at runtime.
*/
const int DynamicIndex = 0xffffff;
/** This value means +Infinity; it is currently used only as the p parameter to MatrixBase::lpNorm().
* The value Infinity there means the L-infinity norm.
*/
const int Infinity = -1;
/** \defgroup flags Flags
* \ingroup Core_Module
*
* These are the possible bits which can be OR'ed to constitute the flags of a matrix or
* expression.
*
* It is important to note that these flags are a purely compile-time notion. They are a compile-time property of
* an expression type, implemented as enum's. They are not stored in memory at runtime, and they do not incur any
* runtime overhead.
*
* \sa MatrixBase::Flags
*/
/** \ingroup flags
*
* for a matrix, this means that the storage order is row-major.
* If this bit is not set, the storage order is column-major.
* For an expression, this determines the storage order of
* the matrix created by evaluation of that expression.
* \sa \ref TopicStorageOrders */
const unsigned int RowMajorBit = 0x1;
/** \ingroup flags
*
* means the expression should be evaluated by the calling expression */
const unsigned int EvalBeforeNestingBit = 0x2;
/** \ingroup flags
*
* means the expression should be evaluated before any assignment */
const unsigned int EvalBeforeAssigningBit = 0x4;
/** \ingroup flags
*
* Short version: means the expression might be vectorized
*
* Long version: means that the coefficients can be handled by packets
* and start at a memory location whose alignment meets the requirements
* of the present CPU architecture for optimized packet access. In the fixed-size
* case, there is the additional condition that it be possible to access all the
* coefficients by packets (this implies the requirement that the size be a multiple of 16 bytes,
* and that any nontrivial strides don't break the alignment). In the dynamic-size case,
* there is no such condition on the total size and strides, so it might not be possible to access
* all coeffs by packets.
*
* \note This bit can be set regardless of whether vectorization is actually enabled.
* To check for actual vectorizability, see \a ActualPacketAccessBit.
*/
const unsigned int PacketAccessBit = 0x8;
#ifdef EIGEN_VECTORIZE
/** \ingroup flags
*
* If vectorization is enabled (EIGEN_VECTORIZE is defined) this constant
* is set to the value \a PacketAccessBit.
*
* If vectorization is not enabled (EIGEN_VECTORIZE is not defined) this constant
* is set to the value 0.
*/
const unsigned int ActualPacketAccessBit = PacketAccessBit;
#else
const unsigned int ActualPacketAccessBit = 0x0;
#endif
/** \ingroup flags
*
* Short version: means the expression can be seen as 1D vector.
*
* Long version: means that one can access the coefficients
* of this expression by coeff(int), and coeffRef(int) in the case of a lvalue expression. These
* index-based access methods are guaranteed
* to not have to do any runtime computation of a (row, col)-pair from the index, so that it
* is guaranteed that whenever it is available, index-based access is at least as fast as
* (row,col)-based access. Expressions for which that isn't possible don't have the LinearAccessBit.
*
* If both PacketAccessBit and LinearAccessBit are set, then the
* packets of this expression can be accessed by packet(int), and writePacket(int) in the case of a
* lvalue expression.
*
* Typically, all vector expressions have the LinearAccessBit, but there is one exception:
* Product expressions don't have it, because it would be troublesome for vectorization, even when the
* Product is a vector expression. Thus, vector Product expressions allow index-based coefficient access but
* not index-based packet access, so they don't have the LinearAccessBit.
*/
const unsigned int LinearAccessBit = 0x10;
/** \ingroup flags
*
* Means the expression has a coeffRef() method, i.e. is writable as its individual coefficients are directly addressable.
* This rules out read-only expressions.
*
* Note that DirectAccessBit and LvalueBit are mutually orthogonal, as there are examples of expression having one but note
* the other:
* \li writable expressions that don't have a very simple memory layout as a strided array, have LvalueBit but not DirectAccessBit
* \li Map-to-const expressions, for example Map, have DirectAccessBit but not LvalueBit
*
* Expressions having LvalueBit also have their coeff() method returning a const reference instead of returning a new value.
*/
const unsigned int LvalueBit = 0x20;
/** \ingroup flags
*
* Means that the underlying array of coefficients can be directly accessed as a plain strided array. The memory layout
* of the array of coefficients must be exactly the natural one suggested by rows(), cols(),
* outerStride(), innerStride(), and the RowMajorBit. This rules out expressions such as Diagonal, whose coefficients,
* though referencable, do not have such a regular memory layout.
*
* See the comment on LvalueBit for an explanation of how LvalueBit and DirectAccessBit are mutually orthogonal.
*/
const unsigned int DirectAccessBit = 0x40;
/** \ingroup flags
*
* means the first coefficient packet is guaranteed to be aligned */
const unsigned int AlignedBit = 0x80;
const unsigned int NestByRefBit = 0x100;
// list of flags that are inherited by default
const unsigned int HereditaryBits = RowMajorBit
| EvalBeforeNestingBit
| EvalBeforeAssigningBit;
/** \defgroup enums Enumerations
* \ingroup Core_Module
*
* Various enumerations used in %Eigen. Many of these are used as template parameters.
*/
/** \ingroup enums
* Enum containing possible values for the \p Mode parameter of
* MatrixBase::selfadjointView() and MatrixBase::triangularView(). */
enum {
/** View matrix as a lower triangular matrix. */
Lower=0x1,
/** View matrix as an upper triangular matrix. */
Upper=0x2,
/** %Matrix has ones on the diagonal; to be used in combination with #Lower or #Upper. */
UnitDiag=0x4,
/** %Matrix has zeros on the diagonal; to be used in combination with #Lower or #Upper. */
ZeroDiag=0x8,
/** View matrix as a lower triangular matrix with ones on the diagonal. */
UnitLower=UnitDiag|Lower,
/** View matrix as an upper triangular matrix with ones on the diagonal. */
UnitUpper=UnitDiag|Upper,
/** View matrix as a lower triangular matrix with zeros on the diagonal. */
StrictlyLower=ZeroDiag|Lower,
/** View matrix as an upper triangular matrix with zeros on the diagonal. */
StrictlyUpper=ZeroDiag|Upper,
/** Used in BandMatrix and SelfAdjointView to indicate that the matrix is self-adjoint. */
SelfAdjoint=0x10,
/** Used to support symmetric, non-selfadjoint, complex matrices. */
Symmetric=0x20
};
/** \ingroup enums
* Enum for indicating whether an object is aligned or not. */
enum {
/** Object is not correctly aligned for vectorization. */
Unaligned=0,
/** Object is aligned for vectorization. */
Aligned=1
};
/** \ingroup enums
* Enum used by DenseBase::corner() in Eigen2 compatibility mode. */
// FIXME after the corner() API change, this was not needed anymore, except by AlignedBox
// TODO: find out what to do with that. Adapt the AlignedBox API ?
enum CornerType { TopLeft, TopRight, BottomLeft, BottomRight };
/** \ingroup enums
* Enum containing possible values for the \p Direction parameter of
* Reverse, PartialReduxExpr and VectorwiseOp. */
enum DirectionType {
/** For Reverse, all columns are reversed;
* for PartialReduxExpr and VectorwiseOp, act on columns. */
Vertical,
/** For Reverse, all rows are reversed;
* for PartialReduxExpr and VectorwiseOp, act on rows. */
Horizontal,
/** For Reverse, both rows and columns are reversed;
* not used for PartialReduxExpr and VectorwiseOp. */
BothDirections
};
/** \internal \ingroup enums
* Enum to specify how to traverse the entries of a matrix. */
enum {
/** \internal Default traversal, no vectorization, no index-based access */
DefaultTraversal,
/** \internal No vectorization, use index-based access to have only one for loop instead of 2 nested loops */
LinearTraversal,
/** \internal Equivalent to a slice vectorization for fixed-size matrices having good alignment
* and good size */
InnerVectorizedTraversal,
/** \internal Vectorization path using a single loop plus scalar loops for the
* unaligned boundaries */
LinearVectorizedTraversal,
/** \internal Generic vectorization path using one vectorized loop per row/column with some
* scalar loops to handle the unaligned boundaries */
SliceVectorizedTraversal,
/** \internal Special case to properly handle incompatible scalar types or other defecting cases*/
InvalidTraversal,
/** \internal Evaluate all entries at once */
AllAtOnceTraversal
};
/** \internal \ingroup enums
* Enum to specify whether to unroll loops when traversing over the entries of a matrix. */
enum {
/** \internal Do not unroll loops. */
NoUnrolling,
/** \internal Unroll only the inner loop, but not the outer loop. */
InnerUnrolling,
/** \internal Unroll both the inner and the outer loop. If there is only one loop,
* because linear traversal is used, then unroll that loop. */
CompleteUnrolling
};
/** \internal \ingroup enums
* Enum to specify whether to use the default (built-in) implementation or the specialization. */
enum {
Specialized,
BuiltIn
};
/** \ingroup enums
* Enum containing possible values for the \p _Options template parameter of
* Matrix, Array and BandMatrix. */
enum {
/** Storage order is column major (see \ref TopicStorageOrders). */
ColMajor = 0,
/** Storage order is row major (see \ref TopicStorageOrders). */
RowMajor = 0x1, // it is only a coincidence that this is equal to RowMajorBit -- don't rely on that
/** Align the matrix itself if it is vectorizable fixed-size */
AutoAlign = 0,
/** Don't require alignment for the matrix itself (the array of coefficients, if dynamically allocated, may still be requested to be aligned) */ // FIXME --- clarify the situation
DontAlign = 0x2
};
/** \ingroup enums
* Enum for specifying whether to apply or solve on the left or right. */
enum {
/** Apply transformation on the left. */
OnTheLeft = 1,
/** Apply transformation on the right. */
OnTheRight = 2
};
/* the following used to be written as:
*
* struct NoChange_t {};
* namespace {
* EIGEN_UNUSED NoChange_t NoChange;
* }
*
* on the ground that it feels dangerous to disambiguate overloaded functions on enum/integer types.
* However, this leads to "variable declared but never referenced" warnings on Intel Composer XE,
* and we do not know how to get rid of them (bug 450).
*/
enum NoChange_t { NoChange };
enum Sequential_t { Sequential };
enum Default_t { Default };
/** \internal \ingroup enums
* Used in AmbiVector. */
enum {
IsDense = 0,
IsSparse
};
/** \ingroup enums
* Used as template parameter in DenseCoeffBase and MapBase to indicate
* which accessors should be provided. */
enum AccessorLevels {
/** Read-only access via a member function. */
ReadOnlyAccessors,
/** Read/write access via member functions. */
WriteAccessors,
/** Direct read-only access to the coefficients. */
DirectAccessors,
/** Direct read/write access to the coefficients. */
DirectWriteAccessors
};
/** \ingroup enums
* Enum with options to give to various decompositions. */
enum DecompositionOptions {
/** \internal Not used (meant for LDLT?). */
Pivoting = 0x01,
/** \internal Not used (meant for LDLT?). */
NoPivoting = 0x02,
/** Used in JacobiSVD to indicate that the square matrix U is to be computed. */
ComputeFullU = 0x04,
/** Used in JacobiSVD to indicate that the thin matrix U is to be computed. */
ComputeThinU = 0x08,
/** Used in JacobiSVD to indicate that the square matrix V is to be computed. */
ComputeFullV = 0x10,
/** Used in JacobiSVD to indicate that the thin matrix V is to be computed. */
ComputeThinV = 0x20,
/** Used in SelfAdjointEigenSolver and GeneralizedSelfAdjointEigenSolver to specify
* that only the eigenvalues are to be computed and not the eigenvectors. */
EigenvaluesOnly = 0x40,
/** Used in SelfAdjointEigenSolver and GeneralizedSelfAdjointEigenSolver to specify
* that both the eigenvalues and the eigenvectors are to be computed. */
ComputeEigenvectors = 0x80,
/** \internal */
EigVecMask = EigenvaluesOnly | ComputeEigenvectors,
/** Used in GeneralizedSelfAdjointEigenSolver to indicate that it should
* solve the generalized eigenproblem \f$ Ax = \lambda B x \f$. */
Ax_lBx = 0x100,
/** Used in GeneralizedSelfAdjointEigenSolver to indicate that it should
* solve the generalized eigenproblem \f$ ABx = \lambda x \f$. */
ABx_lx = 0x200,
/** Used in GeneralizedSelfAdjointEigenSolver to indicate that it should
* solve the generalized eigenproblem \f$ BAx = \lambda x \f$. */
BAx_lx = 0x400,
/** \internal */
GenEigMask = Ax_lBx | ABx_lx | BAx_lx
};
/** \ingroup enums
* Possible values for the \p QRPreconditioner template parameter of JacobiSVD. */
enum QRPreconditioners {
/** Do not specify what is to be done if the SVD of a non-square matrix is asked for. */
NoQRPreconditioner,
/** Use a QR decomposition without pivoting as the first step. */
HouseholderQRPreconditioner,
/** Use a QR decomposition with column pivoting as the first step. */
ColPivHouseholderQRPreconditioner,
/** Use a QR decomposition with full pivoting as the first step. */
FullPivHouseholderQRPreconditioner
};
#ifdef Success
#error The preprocessor symbol 'Success' is defined, possibly by the X11 header file X.h
#endif
/** \ingroup enums
* Enum for reporting the status of a computation. */
enum ComputationInfo {
/** Computation was successful. */
Success = 0,
/** The provided data did not satisfy the prerequisites. */
NumericalIssue = 1,
/** Iterative procedure did not converge. */
NoConvergence = 2,
/** The inputs are invalid, or the algorithm has been improperly called.
* When assertions are enabled, such errors trigger an assert. */
InvalidInput = 3
};
/** \ingroup enums
* Enum used to specify how a particular transformation is stored in a matrix.
* \sa Transform, Hyperplane::transform(). */
enum TransformTraits {
/** Transformation is an isometry. */
Isometry = 0x1,
/** Transformation is an affine transformation stored as a (Dim+1)^2 matrix whose last row is
* assumed to be [0 ... 0 1]. */
Affine = 0x2,
/** Transformation is an affine transformation stored as a (Dim) x (Dim+1) matrix. */
AffineCompact = 0x10 | Affine,
/** Transformation is a general projective transformation stored as a (Dim+1)^2 matrix. */
Projective = 0x20
};
/** \internal \ingroup enums
* Enum used to choose between implementation depending on the computer architecture. */
namespace Architecture
{
enum Type {
Generic = 0x0,
SSE = 0x1,
AltiVec = 0x2,
#if defined EIGEN_VECTORIZE_SSE
Target = SSE
#elif defined EIGEN_VECTORIZE_ALTIVEC
Target = AltiVec
#else
Target = Generic
#endif
};
}
/** \internal \ingroup enums
* Enum used as template parameter in GeneralProduct. */
enum { CoeffBasedProductMode, LazyCoeffBasedProductMode, OuterProduct, InnerProduct, GemvProduct, GemmProduct };
/** \internal \ingroup enums
* Enum used in experimental parallel implementation. */
enum Action {GetAction, SetAction};
/** The type used to identify a dense storage. */
struct Dense {};
/** The type used to identify a matrix expression */
struct MatrixXpr {};
/** The type used to identify an array expression */
struct ArrayXpr {};
} // end namespace Eigen
#endif // EIGEN_CONSTANTS_H