rx

erfa.rx(phi, r)[source]

Rotate an r-matrix about the x-axis.

Parameters:
phidouble array
rdouble array
Returns:
rdouble array

Notes

Wraps ERFA function eraRx. Note that, unlike the erfa routine, the python wrapper does not change r in-place. The ERFA documentation is:

- - - - - -
 e r a R x
- - - - - -

Rotate an r-matrix about the x-axis.

Given:
   phi    double          angle (radians)

Given and returned:
   r      double[3][3]    r-matrix, rotated

Notes:

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

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

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

This revision:  2021 May 11

Copyright (C) 2013-2023, NumFOCUS Foundation.
Derived, with permission, from the SOFA library.  See notes at end of file.