Calculate the pitch, roll and heading for triaxial movement signalsi

    Args
    ----
    ax: ndarray
        x-axis acceleration values
    ay: ndarray
        y-axis acceleration values
    az: ndarray
        z-axis acceleration values

    Returns
    -------
    pitch: ndarray
        Pitch angle in radians
    roll: ndarray
        Pitch angle in radians
    yaw: ndarray
        Pitch angle in radians

def prh(ax, ay, az):
    '''Calculate the pitch, roll and heading for triaxial movement signalsi

    Args
    ----
    ax: ndarray
        x-axis acceleration values
    ay: ndarray
        y-axis acceleration values
    az: ndarray
        z-axis acceleration values

    Returns
    -------
    pitch: ndarray
        Pitch angle in radians
    roll: ndarray
        Pitch angle in radians
    yaw: ndarray
        Pitch angle in radians
    '''

    p = pitch(ax, ay, az)
    r = roll(ax, ay, az)
    y = yaw(ax, ay, az)

    #from dtag_toolbox_python.dtag2 import a2pr
    #pitch, roll, A_norm = a2pr.a2pr(A_g)

    return p, r, y