'Calculate the normalizing factor explained in appendix of sketch-rnn.'

def calculate_normalizing_scale_factor(self):

    data = []
    for i in range(len(self.strokes)):
        if (len(self.strokes[i]) > self.max_seq_length):
            continue
        for j in range(len(self.strokes[i])):
            data.append(self.strokes[i][(j, 0)])
            data.append(self.strokes[i][(j, 1)])
    data = np.array(data)
    return np.std(data)
