A class representing a four-dimensional axis set, extending the AxisSet3D class with an additional fourth axis.
Examples
# Create NamedAxis objects for each dimension
x_axis <- new("NamedAxis", axis = "x", direction = 1)
y_axis <- new("NamedAxis", axis = "y", direction = 1)
z_axis <- new("NamedAxis", axis = "z", direction = 1)
t_axis <- new("NamedAxis", axis = "t", direction = 1)
# Create an AxisSet4D object
axis_set_4d <- new("AxisSet4D", i = x_axis, j = y_axis, k = z_axis,
l = t_axis, ndim = 4L)