merge with tip

This commit is contained in:
Thomas Capricelli
2009-09-10 02:37:08 +02:00
91 changed files with 2602 additions and 905 deletions

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@@ -94,8 +94,6 @@ namespace Eigen {
* responsibility of the intersectObject function to keep track of the results in whatever manner is appropriate.
* The cartesian product intersection and the BVMinimize queries are similar--see their individual documentation.
*
* \addexample BVH_Example \label How to use a BVH to find the closest pair between two point sets
*
* The following is a simple but complete example for how to use the BVH to accelerate the search for a closest red-blue point pair:
* \include BVH_Example.cpp
* Output: \verbinclude BVH_Example.out

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@@ -25,6 +25,10 @@
#ifndef EIGEN_MATRIX_EXPONENTIAL
#define EIGEN_MATRIX_EXPONENTIAL
#ifdef _MSC_VER
template <typename Scalar> Scalar log2(Scalar v) { return std::log(v)/std::log(Scalar(2)); }
#endif
/** \brief Compute the matrix exponential.
*
* \param M matrix whose exponential is to be computed.
@@ -61,257 +65,243 @@ template <typename Derived>
EIGEN_STRONG_INLINE void ei_matrix_exponential(const MatrixBase<Derived> &M,
typename MatrixBase<Derived>::PlainMatrixType* result);
/** \brief Class for computing the matrix exponential.*/
template <typename MatrixType>
class MatrixExponential {
/** \internal \brief Internal helper functions for computing the
* matrix exponential.
*/
namespace MatrixExponentialInternal {
public:
/** \brief Compute the matrix exponential.
*
* \param M matrix whose exponential is to be computed.
* \param result pointer to the matrix in which to store the result.
*/
MatrixExponential(const MatrixType &M, MatrixType *result);
#ifdef _MSC_VER
template <typename Scalar> Scalar log2(Scalar v) { return std::log(v)/std::log(Scalar(2)); }
#endif
private:
// Prevent copying
MatrixExponential(const MatrixExponential&);
MatrixExponential& operator=(const MatrixExponential&);
/** \brief Compute the (3,3)-Pad&eacute; approximant to the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(A) \f$ around \f$ A = 0 \f$.
*
* \param A Argument of matrix exponential
*/
void pade3(const MatrixType &A);
/** \brief Compute the (5,5)-Pad&eacute; approximant to the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(A) \f$ around \f$ A = 0 \f$.
*
* \param A Argument of matrix exponential
*/
void pade5(const MatrixType &A);
/** \brief Compute the (7,7)-Pad&eacute; approximant to the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(A) \f$ around \f$ A = 0 \f$.
*
* \param A Argument of matrix exponential
*/
void pade7(const MatrixType &A);
/** \brief Compute the (9,9)-Pad&eacute; approximant to the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(A) \f$ around \f$ A = 0 \f$.
*
* \param A Argument of matrix exponential
*/
void pade9(const MatrixType &A);
/** \brief Compute the (13,13)-Pad&eacute; approximant to the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(A) \f$ around \f$ A = 0 \f$.
*
* \param A Argument of matrix exponential
*/
void pade13(const MatrixType &A);
/** \brief Compute Pad&eacute; approximant to the exponential.
*
* Computes \c m_U, \c m_V and \c m_squarings such that
* \f$ (V+U)(V-U)^{-1} \f$ is a Pad&eacute; of
* \f$ \exp(2^{-\mbox{squarings}}M) \f$ around \f$ M = 0 \f$. The
* degree of the Pad&eacute; approximant and the value of
* squarings are chosen such that the approximation error is no
* more than the round-off error.
*
* The argument of this function should correspond with the (real
* part of) the entries of \c m_M. It is used to select the
* correct implementation using overloading.
*/
void computeUV(double);
/** \brief Compute Pad&eacute; approximant to the exponential.
*
* \sa computeUV(double);
*/
void computeUV(float);
/** \internal \brief Compute the (3,3)-Pad&eacute; approximant to
* the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(M) \f$ around \f$ M = 0 \f$.
*
* \param M Argument of matrix exponential
* \param Id Identity matrix of same size as M
* \param tmp Temporary storage, to be provided by the caller
* \param M2 Temporary storage, to be provided by the caller
* \param U Even-degree terms in numerator of Pad&eacute; approximant
* \param V Odd-degree terms in numerator of Pad&eacute; approximant
*/
template <typename MatrixType>
EIGEN_STRONG_INLINE void pade3(const MatrixType &M, const MatrixType& Id, MatrixType& tmp,
MatrixType& M2, MatrixType& U, MatrixType& V)
{
typedef typename ei_traits<MatrixType>::Scalar Scalar;
const Scalar b[] = {120., 60., 12., 1.};
M2 = (M * M).lazy();
tmp = b[3]*M2 + b[1]*Id;
U = (M * tmp).lazy();
V = b[2]*M2 + b[0]*Id;
}
/** \internal \brief Compute the (5,5)-Pad&eacute; approximant to
* the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(M) \f$ around \f$ M = 0 \f$.
*
* \param M Argument of matrix exponential
* \param Id Identity matrix of same size as M
* \param tmp Temporary storage, to be provided by the caller
* \param M2 Temporary storage, to be provided by the caller
* \param U Even-degree terms in numerator of Pad&eacute; approximant
* \param V Odd-degree terms in numerator of Pad&eacute; approximant
*/
template <typename MatrixType>
EIGEN_STRONG_INLINE void pade5(const MatrixType &M, const MatrixType& Id, MatrixType& tmp,
MatrixType& M2, MatrixType& U, MatrixType& V)
{
typedef typename ei_traits<MatrixType>::Scalar Scalar;
const Scalar b[] = {30240., 15120., 3360., 420., 30., 1.};
M2 = (M * M).lazy();
MatrixType M4 = (M2 * M2).lazy();
tmp = b[5]*M4 + b[3]*M2 + b[1]*Id;
U = (M * tmp).lazy();
V = b[4]*M4 + b[2]*M2 + b[0]*Id;
}
/** \internal \brief Compute the (7,7)-Pad&eacute; approximant to
* the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(M) \f$ around \f$ M = 0 \f$.
*
* \param M Argument of matrix exponential
* \param Id Identity matrix of same size as M
* \param tmp Temporary storage, to be provided by the caller
* \param M2 Temporary storage, to be provided by the caller
* \param U Even-degree terms in numerator of Pad&eacute; approximant
* \param V Odd-degree terms in numerator of Pad&eacute; approximant
*/
template <typename MatrixType>
EIGEN_STRONG_INLINE void pade7(const MatrixType &M, const MatrixType& Id, MatrixType& tmp,
MatrixType& M2, MatrixType& U, MatrixType& V)
{
typedef typename ei_traits<MatrixType>::Scalar Scalar;
const Scalar b[] = {17297280., 8648640., 1995840., 277200., 25200., 1512., 56., 1.};
M2 = (M * M).lazy();
MatrixType M4 = (M2 * M2).lazy();
MatrixType M6 = (M4 * M2).lazy();
tmp = b[7]*M6 + b[5]*M4 + b[3]*M2 + b[1]*Id;
U = (M * tmp).lazy();
V = b[6]*M6 + b[4]*M4 + b[2]*M2 + b[0]*Id;
}
/** \internal \brief Compute the (9,9)-Pad&eacute; approximant to
* the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(M) \f$ around \f$ M = 0 \f$.
*
* \param M Argument of matrix exponential
* \param Id Identity matrix of same size as M
* \param tmp Temporary storage, to be provided by the caller
* \param M2 Temporary storage, to be provided by the caller
* \param U Even-degree terms in numerator of Pad&eacute; approximant
* \param V Odd-degree terms in numerator of Pad&eacute; approximant
*/
template <typename MatrixType>
EIGEN_STRONG_INLINE void pade9(const MatrixType &M, const MatrixType& Id, MatrixType& tmp,
MatrixType& M2, MatrixType& U, MatrixType& V)
{
typedef typename ei_traits<MatrixType>::Scalar Scalar;
const Scalar b[] = {17643225600., 8821612800., 2075673600., 302702400., 30270240.,
typedef typename NumTraits<typename ei_traits<MatrixType>::Scalar>::Real RealScalar;
/** \brief Pointer to matrix whose exponential is to be computed. */
const MatrixType* m_M;
/** \brief Even-degree terms in numerator of Pad&eacute; approximant. */
MatrixType m_U;
/** \brief Odd-degree terms in numerator of Pad&eacute; approximant. */
MatrixType m_V;
/** \brief Used for temporary storage. */
MatrixType m_tmp1;
/** \brief Used for temporary storage. */
MatrixType m_tmp2;
/** \brief Identity matrix of the same size as \c m_M. */
MatrixType m_Id;
/** \brief Number of squarings required in the last step. */
int m_squarings;
/** \brief L1 norm of m_M. */
float m_l1norm;
};
template <typename MatrixType>
MatrixExponential<MatrixType>::MatrixExponential(const MatrixType &M, MatrixType *result) :
m_M(&M),
m_U(M.rows(),M.cols()),
m_V(M.rows(),M.cols()),
m_tmp1(M.rows(),M.cols()),
m_tmp2(M.rows(),M.cols()),
m_Id(MatrixType::Identity(M.rows(), M.cols())),
m_squarings(0),
m_l1norm(static_cast<float>(M.cwise().abs().colwise().sum().maxCoeff()))
{
computeUV(RealScalar());
m_tmp1 = m_U + m_V; // numerator of Pade approximant
m_tmp2 = -m_U + m_V; // denominator of Pade approximant
m_tmp2.partialLu().solve(m_tmp1, result);
for (int i=0; i<m_squarings; i++)
*result *= *result; // undo scaling by repeated squaring
}
template <typename MatrixType>
EIGEN_STRONG_INLINE void MatrixExponential<MatrixType>::pade3(const MatrixType &A)
{
const Scalar b[] = {120., 60., 12., 1.};
m_tmp1.noalias() = A * A;
m_tmp2 = b[3]*m_tmp1 + b[1]*m_Id;
m_U.noalias() = A * m_tmp2;
m_V = b[2]*m_tmp1 + b[0]*m_Id;
}
template <typename MatrixType>
EIGEN_STRONG_INLINE void MatrixExponential<MatrixType>::pade5(const MatrixType &A)
{
const Scalar b[] = {30240., 15120., 3360., 420., 30., 1.};
MatrixType A2 = A * A;
m_tmp1.noalias() = A2 * A2;
m_tmp2 = b[5]*m_tmp1 + b[3]*A2 + b[1]*m_Id;
m_U.noalias() = A * m_tmp2;
m_V = b[4]*m_tmp1 + b[2]*A2 + b[0]*m_Id;
}
template <typename MatrixType>
EIGEN_STRONG_INLINE void MatrixExponential<MatrixType>::pade7(const MatrixType &A)
{
const Scalar b[] = {17297280., 8648640., 1995840., 277200., 25200., 1512., 56., 1.};
MatrixType A2 = A * A;
MatrixType A4 = A2 * A2;
m_tmp1.noalias() = A4 * A2;
m_tmp2 = b[7]*m_tmp1 + b[5]*A4 + b[3]*A2 + b[1]*m_Id;
m_U.noalias() = A * m_tmp2;
m_V = b[6]*m_tmp1 + b[4]*A4 + b[2]*A2 + b[0]*m_Id;
}
template <typename MatrixType>
EIGEN_STRONG_INLINE void MatrixExponential<MatrixType>::pade9(const MatrixType &A)
{
const Scalar b[] = {17643225600., 8821612800., 2075673600., 302702400., 30270240.,
2162160., 110880., 3960., 90., 1.};
M2 = (M * M).lazy();
MatrixType M4 = (M2 * M2).lazy();
MatrixType M6 = (M4 * M2).lazy();
MatrixType M8 = (M6 * M2).lazy();
tmp = b[9]*M8 + b[7]*M6 + b[5]*M4 + b[3]*M2 + b[1]*Id;
U = (M * tmp).lazy();
V = b[8]*M8 + b[6]*M6 + b[4]*M4 + b[2]*M2 + b[0]*Id;
}
/** \internal \brief Compute the (13,13)-Pad&eacute; approximant to
* the exponential.
*
* After exit, \f$ (V+U)(V-U)^{-1} \f$ is the Pad&eacute;
* approximant of \f$ \exp(M) \f$ around \f$ M = 0 \f$.
*
* \param M Argument of matrix exponential
* \param Id Identity matrix of same size as M
* \param tmp Temporary storage, to be provided by the caller
* \param M2 Temporary storage, to be provided by the caller
* \param U Even-degree terms in numerator of Pad&eacute; approximant
* \param V Odd-degree terms in numerator of Pad&eacute; approximant
*/
template <typename MatrixType>
EIGEN_STRONG_INLINE void pade13(const MatrixType &M, const MatrixType& Id, MatrixType& tmp,
MatrixType& M2, MatrixType& U, MatrixType& V)
{
typedef typename ei_traits<MatrixType>::Scalar Scalar;
const Scalar b[] = {64764752532480000., 32382376266240000., 7771770303897600.,
MatrixType A2 = A * A;
MatrixType A4 = A2 * A2;
MatrixType A6 = A4 * A2;
m_tmp1.noalias() = A6 * A2;
m_tmp2 = b[9]*m_tmp1 + b[7]*A6 + b[5]*A4 + b[3]*A2 + b[1]*m_Id;
m_U.noalias() = A * m_tmp2;
m_V = b[8]*m_tmp1 + b[6]*A6 + b[4]*A4 + b[2]*A2 + b[0]*m_Id;
}
template <typename MatrixType>
EIGEN_STRONG_INLINE void MatrixExponential<MatrixType>::pade13(const MatrixType &A)
{
const Scalar b[] = {64764752532480000., 32382376266240000., 7771770303897600.,
1187353796428800., 129060195264000., 10559470521600., 670442572800.,
33522128640., 1323241920., 40840800., 960960., 16380., 182., 1.};
M2 = (M * M).lazy();
MatrixType M4 = (M2 * M2).lazy();
MatrixType M6 = (M4 * M2).lazy();
V = b[13]*M6 + b[11]*M4 + b[9]*M2;
tmp = (M6 * V).lazy();
tmp += b[7]*M6 + b[5]*M4 + b[3]*M2 + b[1]*Id;
U = (M * tmp).lazy();
tmp = b[12]*M6 + b[10]*M4 + b[8]*M2;
V = (M6 * tmp).lazy();
V += b[6]*M6 + b[4]*M4 + b[2]*M2 + b[0]*Id;
}
/** \internal \brief Helper class for computing Pad&eacute;
* approximants to the exponential.
*/
template <typename MatrixType, typename RealScalar = typename NumTraits<typename ei_traits<MatrixType>::Scalar>::Real>
struct computeUV_selector
{
/** \internal \brief Compute Pad&eacute; approximant to the exponential.
*
* Computes \p U, \p V and \p squarings such that \f$ (V+U)(V-U)^{-1} \f$
* is a Pad&eacute; of \f$ \exp(2^{-\mbox{squarings}}M) \f$
* around \f$ M = 0 \f$. The degree of the Pad&eacute;
* approximant and the value of squarings are chosen such that
* the approximation error is no more than the round-off error.
*
* \param M Argument of matrix exponential
* \param Id Identity matrix of same size as M
* \param tmp1 Temporary storage, to be provided by the caller
* \param tmp2 Temporary storage, to be provided by the caller
* \param U Even-degree terms in numerator of Pad&eacute; approximant
* \param V Odd-degree terms in numerator of Pad&eacute; approximant
* \param l1norm L<sub>1</sub> norm of M
* \param squarings Pointer to integer containing number of times
* that the result needs to be squared to find the
* matrix exponential
*/
static void run(const MatrixType &M, const MatrixType& Id, MatrixType& tmp1, MatrixType& tmp2,
MatrixType& U, MatrixType& V, float l1norm, int* squarings);
};
template <typename MatrixType>
struct computeUV_selector<MatrixType, float>
{
static void run(const MatrixType &M, const MatrixType& Id, MatrixType& tmp1, MatrixType& tmp2,
MatrixType& U, MatrixType& V, float l1norm, int* squarings)
{
*squarings = 0;
if (l1norm < 4.258730016922831e-001) {
pade3(M, Id, tmp1, tmp2, U, V);
} else if (l1norm < 1.880152677804762e+000) {
pade5(M, Id, tmp1, tmp2, U, V);
} else {
const float maxnorm = 3.925724783138660;
*squarings = std::max(0, (int)ceil(log2(l1norm / maxnorm)));
MatrixType A = M / std::pow(typename ei_traits<MatrixType>::Scalar(2), *squarings);
pade7(A, Id, tmp1, tmp2, U, V);
}
}
};
template <typename MatrixType>
struct computeUV_selector<MatrixType, double>
{
static void run(const MatrixType &M, const MatrixType& Id, MatrixType& tmp1, MatrixType& tmp2,
MatrixType& U, MatrixType& V, float l1norm, int* squarings)
{
*squarings = 0;
if (l1norm < 1.495585217958292e-002) {
pade3(M, Id, tmp1, tmp2, U, V);
} else if (l1norm < 2.539398330063230e-001) {
pade5(M, Id, tmp1, tmp2, U, V);
} else if (l1norm < 9.504178996162932e-001) {
pade7(M, Id, tmp1, tmp2, U, V);
} else if (l1norm < 2.097847961257068e+000) {
pade9(M, Id, tmp1, tmp2, U, V);
} else {
const double maxnorm = 5.371920351148152;
*squarings = std::max(0, (int)ceil(log2(l1norm / maxnorm)));
MatrixType A = M / std::pow(typename ei_traits<MatrixType>::Scalar(2), *squarings);
pade13(A, Id, tmp1, tmp2, U, V);
}
}
};
/** \internal \brief Compute the matrix exponential.
*
* \param M matrix whose exponential is to be computed.
* \param result pointer to the matrix in which to store the result.
*/
template <typename MatrixType>
void compute(const MatrixType &M, MatrixType* result)
{
MatrixType num, den, U, V;
MatrixType Id = MatrixType::Identity(M.rows(), M.cols());
float l1norm = M.cwise().abs().colwise().sum().maxCoeff();
int squarings;
computeUV_selector<MatrixType>::run(M, Id, num, den, U, V, l1norm, &squarings);
num = U + V; // numerator of Pade approximant
den = -U + V; // denominator of Pade approximant
den.partialLu().solve(num, result);
for (int i=0; i<squarings; i++)
*result *= *result; // undo scaling by repeated squaring
}
MatrixType A2 = A * A;
MatrixType A4 = A2 * A2;
m_tmp1.noalias() = A4 * A2;
m_V = b[13]*m_tmp1 + b[11]*A4 + b[9]*A2; // used for temporary storage
m_tmp2.noalias() = m_tmp1 * m_V;
m_tmp2 += b[7]*m_tmp1 + b[5]*A4 + b[3]*A2 + b[1]*m_Id;
m_U.noalias() = A * m_tmp2;
m_tmp2 = b[12]*m_tmp1 + b[10]*A4 + b[8]*A2;
m_V.noalias() = m_tmp1 * m_tmp2;
m_V += b[6]*m_tmp1 + b[4]*A4 + b[2]*A2 + b[0]*m_Id;
}
} // end of namespace MatrixExponentialInternal
template <typename MatrixType>
void MatrixExponential<MatrixType>::computeUV(float)
{
if (m_l1norm < 4.258730016922831e-001) {
pade3(*m_M);
} else if (m_l1norm < 1.880152677804762e+000) {
pade5(*m_M);
} else {
const float maxnorm = 3.925724783138660f;
m_squarings = std::max(0, (int)ceil(log2(m_l1norm / maxnorm)));
MatrixType A = *m_M / std::pow(Scalar(2), m_squarings);
pade7(A);
}
}
template <typename MatrixType>
void MatrixExponential<MatrixType>::computeUV(double)
{
if (m_l1norm < 1.495585217958292e-002) {
pade3(*m_M);
} else if (m_l1norm < 2.539398330063230e-001) {
pade5(*m_M);
} else if (m_l1norm < 9.504178996162932e-001) {
pade7(*m_M);
} else if (m_l1norm < 2.097847961257068e+000) {
pade9(*m_M);
} else {
const double maxnorm = 5.371920351148152;
m_squarings = std::max(0, (int)ceil(log2(m_l1norm / maxnorm)));
MatrixType A = *m_M / std::pow(Scalar(2), m_squarings);
pade13(A);
}
}
template <typename Derived>
EIGEN_STRONG_INLINE void ei_matrix_exponential(const MatrixBase<Derived> &M,
typename MatrixBase<Derived>::PlainMatrixType* result)
{
ei_assert(M.rows() == M.cols());
MatrixExponentialInternal::compute(M.eval(), result);
MatrixExponential<typename MatrixBase<Derived>::PlainMatrixType>(M, result);
}
#endif // EIGEN_MATRIX_EXPONENTIAL

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@@ -211,7 +211,6 @@ ALIASES = "only_for_vectors=This is only for vectors (either row-
"svd_module=This is defined in the %SVD module. \code #include <Eigen/SVD> \endcode" \
"geometry_module=This is defined in the %Geometry module. \code #include <Eigen/Geometry> \endcode" \
"leastsquares_module=This is defined in the %LeastSquares module. \code #include <Eigen/LeastSquares> \endcode" \
"addexample=\anchor" \
"label=\bug" \
"redstar=<a href='#warningarraymodule' style='color:red;text-decoration: none;'>*</a>" \
"nonstableyet=\warning This is not considered to be part of the stable public API yet. Changes may happen in future releases. See \ref Experimental \"Experimental parts of Eigen\""

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@@ -43,10 +43,10 @@ void test2dRotation(double tol)
A << 0, 1, -1, 0;
for (int i=0; i<=20; i++)
{
angle = pow(10, i / 5. - 2);
angle = static_cast<T>(pow(10, i / 5. - 2));
B << cos(angle), sin(angle), -sin(angle), cos(angle);
ei_matrix_exponential(angle*A, &C);
VERIFY(C.isApprox(B, tol));
VERIFY(C.isApprox(B, static_cast<T>(tol)));
}
}
@@ -59,13 +59,13 @@ void test2dHyperbolicRotation(double tol)
for (int i=0; i<=20; i++)
{
angle = (i-10) / 2.0;
angle = static_cast<T>((i-10) / 2.0);
ch = std::cosh(angle);
sh = std::sinh(angle);
A << 0, angle*imagUnit, -angle*imagUnit, 0;
B << ch, sh*imagUnit, -sh*imagUnit, ch;
ei_matrix_exponential(A, &C);
VERIFY(C.isApprox(B, tol));
VERIFY(C.isApprox(B, static_cast<T>(tol)));
}
}
@@ -77,13 +77,13 @@ void testPascal(double tol)
Matrix<T,Dynamic,Dynamic> A(size,size), B(size,size), C(size,size);
A.setZero();
for (int i=0; i<size-1; i++)
A(i+1,i) = i+1;
A(i+1,i) = static_cast<T>(i+1);
B.setZero();
for (int i=0; i<size; i++)
for (int j=0; j<=i; j++)
B(i,j) = binom(i,j);
B(i,j) = static_cast<T>(binom(i,j));
ei_matrix_exponential(A, &C);
VERIFY(C.isApprox(B, tol));
VERIFY(C.isApprox(B, static_cast<T>(tol)));
}
}
@@ -98,11 +98,13 @@ void randomTest(const MatrixType& m, double tol)
MatrixType m1(rows, cols), m2(rows, cols), m3(rows, cols),
identity = MatrixType::Identity(rows, rows);
typedef typename NumTraits<typename ei_traits<MatrixType>::Scalar>::Real RealScalar;
for(int i = 0; i < g_repeat; i++) {
m1 = MatrixType::Random(rows, cols);
ei_matrix_exponential(m1, &m2);
ei_matrix_exponential(-m1, &m3);
VERIFY(identity.isApprox(m2 * m3, tol));
VERIFY(identity.isApprox(m2 * m3, static_cast<RealScalar>(tol)));
}
}