Function tray_rust::linalg::spherical_dir_coords

pub fn spherical_dir_coords(
    sin_theta: f32, 
    cos_theta: f32, 
    phi: f32, 
    x: &Vector, 
    y: &Vector, 
    z: &Vector
) -> Vector

Compute the direction specified by theta and phi in the coordinate system formed by x, y and z