era.rz.md

eraRz

ERFA.rz(psi, r)

Rotate an r-matrix about the z-axis.

Given:

   psi    double          angle (radians)

Given and returned:

   r      double[3][3]    r-matrix, rotated

Notes:

1. Calling this function with positive psi incorporates in the supplied r-matrix r an additional rotation, about the z-axis, anticlockwise as seen looking towards the origin from positive z.

2) The additional rotation can be represented by this matrix:

       (  + cos(psi)   + sin(psi)     0  )
       (                                 )
       (  - sin(psi)   + cos(psi)     0  )
       (                                 )
       (       0            0         1  )

This revision: 2021 May 11

Copyright (C) 2013-2021, NumFOCUS Foundation. Derived, with permission, from the SOFA library.