sepp¶
- erfa.sepp(a, b)[source]¶
Angular separation between two p-vectors.
- Parameters:
- adouble array
- bdouble array
- Returns:
- c_retvaldouble array
Notes
Wraps ERFA function
eraSepp
. The ERFA documentation is:- - - - - - - - e r a S e p p - - - - - - - - Angular separation between two p-vectors. Given: a double[3] first p-vector (not necessarily unit length) b double[3] second p-vector (not necessarily unit length) Returned (function value): double angular separation (radians, always positive) Notes: 1) If either vector is null, a zero result is returned. 2) The angular separation is most simply formulated in terms of scalar product. However, this gives poor accuracy for angles near zero and pi. The present algorithm uses both cross product and dot product, to deliver full accuracy whatever the size of the angle. Called: eraPxp vector product of two p-vectors eraPm modulus of p-vector eraPdp scalar product of two p-vectors This revision: 2021 May 11 Copyright (C) 2013-2023, NumFOCUS Foundation. Derived, with permission, from the SOFA library. See notes at end of file.