era.pn.md

eraPn

[r, u] = ERFA.pn(p)

Convert a p-vector into modulus and unit vector.

Given:

   p        double[3]      p-vector

Returned:

   r        double         modulus
   u        double[3]      unit vector

Notes:

1. If p is null, the result is null. Otherwise the result is a unit vector.

2. It is permissible to re-use the same array for any of the arguments.

Called:

   eraPm        modulus of p-vector
   eraZp        zero p-vector
   eraSxp       multiply p-vector by scalar

This revision: 2021 May 11

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