Calculate the rotation matrix (direction cosine matrix) `R_EL`

using
n-vector (`n_E`

) and the wander azimuth angle.
When `wander_azimuth = 0`

, we have that N = L (See Table 2 in Gade (2010) for
details)

## Arguments

- n_E
n-vector decomposed in E (3x1 vector) (no unit)

- wander_azimuth
The angle between L's x-axis and north, positive about L's z-axis (rad)

## References

Kenneth Gade A Nonsingular Horizontal Position Representation.
*The Journal of Navigation*, Volume 63, Issue 03, pp 395-417, July 2010.

## Examples

```
# Calculates the rotation matrix (direction cosine matrix) R_EL
# using n-vector (n_E) and the wander azimuth angle.
n_E <- c(1, 0, 0)
(R_EL <- n_E_and_wa2R_EL(n_E, wander_azimuth = pi / 2))
#> [,1] [,2] [,3]
#> [1,] 0.000000e+00 0.000000e+00 -1
#> [2,] 1.000000e+00 6.123234e-17 0
#> [3,] 6.123234e-17 -1.000000e+00 0
```