Python 绘制混淆矩阵函数 confusion_matrix_plot_confusion_matrix函数

Python 绘制混淆矩阵函数 confusion_matrix

代码如下：

def plot_confusion_matrix(y_true, y_pred, labels):
    import matplotlib.pyplot as plt
    from sklearn.metrics import confusion_matrix
    cmap = plt.cm.binary
    cm = confusion_matrix(y_true, y_pred)
    tick_marks = np.array(range(len(labels))) + 0.5
    np.set_printoptions(precision=2)
    cm_normalized = cm.astype('float') / cm.sum(axis=1)[:, np.newaxis]
    plt.figure(figsize=(10, 8), dpi=120)
    ind_array = np.arange(len(labels))
    x, y = np.meshgrid(ind_array, ind_array)
    intFlag = 0 # 标记在图片中对文字是整数型还是浮点型
    for x_val, y_val in zip(x.flatten(), y.flatten()):
        #

        if (intFlag):
            c = cm[y_val][x_val]
            plt.text(x_val, y_val, "%d" % (c,), color='red', fontsize=8, va='center', ha='center')

        else:
            c = cm_normalized[y_val][x_val]
            if (c > 0.01):
                #这里是绘制数字，可以对数字大小和颜色进行修改
                plt.text(x_val, y_val, "%0.2f" % (c,), color='red', fontsize=7, va='center', ha='center')
            else:
                plt.text(x_val, y_val, "%d" % (0,), color='red', fontsize=7, va='center', ha='center')
    if(intFlag):
        plt.imshow(cm, interpolation='nearest', cmap=cmap)
    else:
        plt.imshow(cm_normalized, interpolation='nearest', cmap=cmap)
    plt.gca().set_xticks(tick_marks, minor=True)
    plt.gca().set_yticks(tick_marks, minor=True)
    plt.gca().xaxis.set_ticks_position('none')
    plt.gca().yaxis.set_ticks_position('none')
    plt.grid(True, which='minor', linestyle='-')
    plt.gcf().subplots_adjust(bottom=0.15)
    plt.title('')
    plt.colorbar()
    xlocations = np.array(range(len(labels)))
    plt.xticks(xlocations, labels, rotation=90)
    plt.yticks(xlocations, labels)
    plt.ylabel('Index of True Classes')
    plt.xlabel('Index of Predict Classes')
    plt.savefig('confusion_matrix.jpg', dpi=300)
    plt.show()
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