def getNearestUCDpulse(azimuth, elevation, h3D):
    """
    retrieves the impulse response from h3D that is closest to the specified
    azimuth and elevation (in degrees)
    h3D is the array containing all HRTFs for a given subject (left or right)
    """

    elmax = 50
    elindices = np.arange(elmax)
    elevations = -45 + 5.625 * (elindices-1)
    azimuths = np.concatenate(([-80, -65, -55], np.arange(-45, 45+1, 5), [55, 65, 80]))

    # el est est l'indice du plus proche de l'indicie elevation entré
    el = round ((elevation + 45) / 5.625 + 1)
    el = np.maximum(el, 1)
    el = np.minimum(el, elmax)
    elerr = el - (elevation + 45) / 5.625 + 1

    # azim est l'indice du plus proche de l'indice azimuth entr�
    daz = abs(azimuths - azimuth)
    azim = np.argmin(daz)
    azerr = daz[azim]

    print('les paramètres utilisés pour la HRTF sont:')
    print('\t azimuth: %i degrés' % azimuths[azim])
    print('\t élevation: %6.3f degrés' % (-45 + 5.625 * (el - 1)))
    print('les indices sont:')
    print('\t azim: %i' % azim)
    print('\t el: %d ' % el)

    pulse = np.squeeze(h3D[azim,el,:])
    return pulse, azerr, elerr