Recall :
\[ W^k=W^{k-1}+\alpha d^{k-1} \]
where \(||d^{k-1}||=1\) (ie. normalized) and we just sample from 0 to \(2\pi\) (0 to 360 degrees).
Meaning,
\[ d^{k-1}=\begin{bmatrix}\cos(\theta) \\ \sin(\theta)\end{bmatrix} \]
\[ X \sim \text{Unif}(0,2\pi) \]
random_direction_radians <-
function(num_samp){runif(num_samp, min = 0, max = 2 * pi)}
random_direction_radians
## function(num_samp){runif(num_samp, min = 0, max = 2 * pi)}