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The quaternions were apparently correct after all (except for the ordering of conjugation in vector rotation). 

Former-commit-id: c233f1501a565ad3bbed5933324a0b821d2d1379
This commit is contained in:
Marek Nečada 2019-03-15 21:14:59 +00:00
parent 97f87202e1
commit 3e94b1baec
1 changed files with 3 additions and 15 deletions
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18
qpms/wigner.h
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@ -45,7 +45,7 @@ static inline qpms_quat_t qpms_quat_add(qpms_quat_t p, qpms_quat_t q) {
return r; return r;
} }
/// Exponential function of a quaternion \f$e^Q$\f. MAYBE WRONG. /// Exponential function of a quaternion \f$e^Q$\f.
static inline qpms_quat_t qpms_quat_exp(const qpms_quat_t q) { static inline qpms_quat_t qpms_quat_exp(const qpms_quat_t q) {
const qpms_quat4d_t q4 = qpms_quat_4d_from_2c(q); const qpms_quat4d_t q4 = qpms_quat_4d_from_2c(q);
const double vn = sqrt(q4.ci*q4.ci + q4.cj*q4.cj + q4.ck *q4.ck); const double vn = sqrt(q4.ci*q4.ci + q4.cj*q4.cj + q4.ck *q4.ck);
@ -90,7 +90,7 @@ static inline qpms_quat_t qpms_quat_normalise(qpms_quat_t q) {
return qpms_quat_rscale(1/n, q); return qpms_quat_rscale(1/n, q);
} }
/// Logarithm of a quaternion. MAYBE AND PROBABLY WRONG. /// Logarithm of a quaternion.
static inline qpms_quat_t qpms_quat_log(const qpms_quat_t q) { static inline qpms_quat_t qpms_quat_log(const qpms_quat_t q) {
const double n = qpms_quat_norm(q); const double n = qpms_quat_norm(q);
const double imnorm = qpms_quat_imnorm(q); const double imnorm = qpms_quat_imnorm(q);
@ -106,25 +106,13 @@ static inline qpms_quat_t qpms_quat_log(const qpms_quat_t q) {
} }
} }
/// Quaternion power to a real exponent. PROBABLY WRONG!!! /// Quaternion power to a real exponent.
static inline qpms_quat_t qpms_quat_pow(const qpms_quat_t q, const double exponent) { static inline qpms_quat_t qpms_quat_pow(const qpms_quat_t q, const double exponent) {
const qpms_quat_t qe = qpms_quat_rscale(exponent, const qpms_quat_t qe = qpms_quat_rscale(exponent,
qpms_quat_log(q)); qpms_quat_log(q));
return qpms_quat_exp(qe); return qpms_quat_exp(qe);
} }
#if 0
/// Quaternion conjugation \a q*.
// A very stupid but correct (hopefully) implementation
static inline qpms_quat_t qpms_quat_conj(const qpms_quat_t q) {
return qpms_quat_rscale(-0.5,
qpms_quat_add(q,
qpms_quat_add(qpms_quat_mult(qpms_quat_i,qpms_quat_mult(q,qpms_quat_i)),
qpms_quat_add(qpms_quat_mult(qpms_quat_j,qpms_quat_mult(q,qpms_quat_j)),
qpms_quat_mult(qpms_quat_k,qpms_quat_mult(q,qpms_quat_k))))));
}
#endif
/// Quaternion inversion. /// Quaternion inversion.
/** \f[ q^{-1} = \frac{q*}{|q|}. \f] */ /** \f[ q^{-1} = \frac{q*}{|q|}. \f] */
static inline qpms_quat_t qpms_quat_inv(const qpms_quat_t q) { static inline qpms_quat_t qpms_quat_inv(const qpms_quat_t q) {