def setUp(self):
        itau_data = get_itau_data_from_file()
        self.header_arquivo = itau_data['header_arquivo']
        self.seg_p = itau_data['seg_p1']
        self.seg_p_str = itau_data['seg_p1_str']
        self.seg_q = itau_data['seg_q1']
        self.seg_q_str = itau_data['seg_q1_str']
def voltage_fft(title, order, voltage, ax=0):
    """plot FFT harmonics of voltage"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('{} / V'.format(title))
    ax.grid(True)
    if max(order) < 5:
        order += [5]
        voltage += [0]
    try:
        bw = 2.5E-2*max(order)
        ax.bar(order, voltage, width=bw, align='center')
    except ValueError:  # empty sequence
        pass