1 #ifndef POLARDECOMPOSITION_H
2 #define POLARDECOMPOSITION_H
4 #include "btMatrix3x3.h"
7 * This class is used to compute the polar decomposition of a matrix. In
8 * general, the polar decomposition factorizes a matrix, A, into two parts: a
9 * unitary matrix (U) and a positive, semi-definite Hermitian matrix (H).
10 * However, in this particular implementation the original matrix, A, is
11 * required to be a square 3x3 matrix with real elements. This means that U will
12 * be an orthogonal matrix and H with be a positive-definite, symmetric matrix.
14 class btPolarDecomposition
17 static const btScalar DEFAULT_TOLERANCE;
18 static const unsigned int DEFAULT_MAX_ITERATIONS;
21 * Creates an instance with optional parameters.
23 * @param tolerance - the tolerance used to determine convergence of the
25 * @param maxIterations - the maximum number of iterations used to achieve
28 btPolarDecomposition(btScalar tolerance = DEFAULT_TOLERANCE,
29 unsigned int maxIterations = DEFAULT_MAX_ITERATIONS);
32 * Decomposes a matrix into orthogonal and symmetric, positive-definite
33 * parts. If the number of iterations returned by this function is equal to
34 * the maximum number of iterations, the algorithm has failed to converge.
36 * @param a - the original matrix
37 * @param u - the resulting orthogonal matrix
38 * @param h - the resulting symmetric matrix
40 * @return the number of iterations performed by the algorithm.
42 unsigned int decompose(const btMatrix3x3& a, btMatrix3x3& u, btMatrix3x3& h) const;
45 * Returns the maximum number of iterations that this algorithm will perform
46 * to achieve convergence.
48 * @return maximum number of iterations
50 unsigned int maxIterations() const;
54 unsigned int m_maxIterations;
58 * This functions decomposes the matrix 'a' into two parts: an orthogonal matrix
59 * 'u' and a symmetric, positive-definite matrix 'h'. If the number of
60 * iterations returned by this function is equal to
61 * btPolarDecomposition::DEFAULT_MAX_ITERATIONS, the algorithm has failed to
64 * @param a - the original matrix
65 * @param u - the resulting orthogonal matrix
66 * @param h - the resulting symmetric matrix
68 * @return the number of iterations performed by the algorithm.
70 unsigned int polarDecompose(const btMatrix3x3& a, btMatrix3x3& u, btMatrix3x3& h);
72 #endif // POLARDECOMPOSITION_H