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- move: DerivedTraits becomes MatrixBase::Traits

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- the static constants are private again in the Derived classes
- more documentation and code snippets
- new isDiagonal() method
This commit is contained in:
Benoit Jacob
2008-01-06 16:35:21 +00:00
parent aaf889e72b
commit 84934ea217
40 changed files with 304 additions and 177 deletions
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44
Eigen/src/Core/Identity.h
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@@ -26,6 +26,12 @@
#ifndef EIGEN_IDENTITY_H
#define EIGEN_IDENTITY_H
/** \class Identity
*
* \brief Expression of the identity matrix of some size.
*
* \sa MatrixBase::identity(int)
*/
template<typename MatrixType> class Identity : NoOperatorEquals,
public MatrixBase<typename MatrixType::Scalar, Identity<MatrixType> >
{
@@ -33,15 +39,15 @@ template<typename MatrixType> class Identity : NoOperatorEquals,
typedef typename MatrixType::Scalar Scalar;
friend class MatrixBase<Scalar, Identity<MatrixType> >;
static const int RowsAtCompileTime = MatrixType::RowsAtCompileTime,
ColsAtCompileTime = MatrixType::ColsAtCompileTime;
Identity(int rows) : m_rows(rows)
{
assert(rows > 0 && RowsAtCompileTime == ColsAtCompileTime);
}
private:
static const int RowsAtCompileTime = MatrixType::Traits::RowsAtCompileTime,
ColsAtCompileTime = MatrixType::Traits::ColsAtCompileTime;
const Identity& _ref() const { return *this; }
int _rows() const { return m_rows; }
int _cols() const { return m_rows; }
@@ -55,22 +61,46 @@ template<typename MatrixType> class Identity : NoOperatorEquals,
int m_rows;
};
/** \returns an expression of the identity matrix of given type and size.
*
* \param rows The number of rows of the identity matrix to return. If *this has
* fixed size, that size is used as the default argument for \a rows
* and is then the only allowed value. If *this has dynamic size,
* you can use any positive value for \a rows.
*
* \note An identity matrix is a square matrix, so it is required that the type of *this
* allows being a square matrix.
*
* Example: \include MatrixBase_identity_int.cpp
* Output: \verbinclude MatrixBase_identity_int.out
*
* \sa class Identity, isIdentity()
*/
template<typename Scalar, typename Derived>
const Identity<Derived> MatrixBase<Scalar, Derived>::identity(int rows)
{
return Identity<Derived>(rows);
}
/** \returns true if *this is approximately equal to the identity matrix,
* within the precision given by \a prec.
*
* Example: \include MatrixBase_isIdentity.cpp
* Output: \verbinclude MatrixBase_isIdentity.out
*
* \sa class Identity, identity(int)
*/
template<typename Scalar, typename Derived>
bool MatrixBase<Scalar, Derived>::isIdentity
(const typename NumTraits<Scalar>::Real& prec = precision<Scalar>()) const
(typename NumTraits<Scalar>::Real prec = precision<Scalar>()) const
{
for(int j = 0; j < col(); j++)
if(cols() != rows()) return false;
for(int j = 0; j < cols(); j++)
{
if(!isApprox(coeff(j, j), static_cast<Scalar>(1)))
if(!Eigen::isApprox(coeff(j, j), static_cast<Scalar>(1), prec))
return false;
for(int i = 0; i < j; i++)
if(!isMuchSmallerThan(coeff(i, j), static_cast<Scalar>(1)))
if(!Eigen::isMuchSmallerThan(coeff(i, j), static_cast<Scalar>(1), prec))
return false;
}
return true;