[Python] (Multiple) Histogram Plot

    # https://matplotlib.org/examples/statistics/histogram_demo_multihist.html
    fig, histograms = plt.subplots(nrows=1, ncols=2)
    hist0, hist1 = histograms.flatten()

    colors = ['red', 'blue']
    hist0.hist(
        flatten_kernels[np.nonzero(flatten_kernels)],
        bin_num,
        histtype='bar',
        color=colors[0],
        label='Weights')
    hist0.set_title("Layer " + str(layer_cfg.layer_id))
    hist0.set_xlabel('Bin values')
    hist0.set_ylabel('Value occurence')

    hist1.hist(layer_cfg.bias, bin_num, histtype='bar', color=colors[1])
    hist1.set_title("Biases, layer " + str(layer_cfg.layer_id))
    hist1.set_xlabel('Bin values')
    hist1.set_ylabel('Value occurence')

    fig.tight_layout()
    plt.grid(True)
    plt.show()

    # n, bins, patches = plt.hist(
    #     flatten_kernels[np.nonzero(flatten_kernels)],
    #     bin_num,
    #     facecolor='green',
    #     label='Weights',
    #     alpha=0.75)

    # n, bins, patches = plt.hist(
    #     layer_cfg.bias, bin_num, facecolor='blue', label='Biases', alpha=0.75)

    # plt.xlabel('Bins')
    # plt.ylabel('Max value occurence')
    # plt.title("Layer " + str(layer_cfg.layer_id))
    # plt.grid(True)