"""Converts a quaternion to axis-angle format.

The function transforms a quaternion representation of a rotation into its corresponding
axis-angle format, where the rotation is represented by a unit vector (axis) scaled by the
angle of rotation in radians.

Args:
    quat (np.array): A quaternion represented as a 4-element array (x, y, z, w) of float values.

Returns:
    np.array: A 3-element array (ax, ay, az) representing the axis-angle exponential coordinates,
              where the vector is the axis of rotation scaled by the angle in radians.
"""
You should write code starting with:
from scipy.spatial.transform import Rotation as R
import numpy as np

def quat2axisangle(quat: np.array) -> np.array:
    # TODO: Implement this function
    pass

