Complete the classification of CIFAR-10 data set and UCI wine data set based on MLP

Completed the classification of CIFAR-10 data set and UCI wine data set based on MLP, used sklearn and tensorflow, and performed data visualization display for image classification

Dataset introduction

UCI wine data set:

http://archive.ics.uci.edu/dataset/109/wine

The data are the result of a chemical analysis of wine grown in the same region of Italy, but from three different varieties. The analysis determined the amounts of 13 ingredients found in each of the three wines.

CIFAR-10 data set:

https://www.cs.toronto.edu/~kriz/cifar.html

The CIFAR-10 data set consists of 60,000 32x32 color images in 10 categories, with 6,000 images in each category. There are 50,000 training images and 10,000 testing images.

The data set is divided into 5 training batches and 1 testing batch, each batch has 10,000 images. The test batch contains exactly 1000 randomly selected images from each class. The training batches contain the remaining images in random order, but some training batches may contain more images from one class than another. Between them, the training batch contains exactly 5000 images from each class

MLP algorithm

MLP stands for Multilayer Perceptron and is a basic feedforward neural network model. It consists of an input layer, one or more hidden layers, and an output layer, where each layer contains multiple neurons (or nodes). MLP is a powerful model commonly used to solve classification and regression problems.

The basic components of an MLP are as follows:

• Input Layer: The input layer that receives the original data. Each input node corresponds to the input feature.

• Hidden Layer:
  One or more layers of neurons located between the input layer and the output layer. Each neuron is connected to all nodes of the previous layer through weights and undergoes nonlinear transformation through activation functions. The existence of hidden layers enables the network to learn complex features of the input data.

• Output Layer: Provides the final network output. For different problems, the activation function of the output layer may be different. For example, for binary classification problems, you can use
  the sigmoid activation function; for multi-classification problems, you can use the softmax activation function.

Model building

UCI wine：

We load load_wine in sklearn.datasets as training data, divide it into a data set and a test set, and perform standardization operations

Then call MLPClassifier(hidden_layer_sizes=(100,), max_iter=1000, random_state=42) to create the model

After training, predict on the test set, and finally evaluate the model

from sklearn.neural_network import MLPClassifier
from sklearn.datasets import load_iris
from sklearn.datasets import load_wine
from sklearn.model_selection import train_test_split
from sklearn.metrics import accuracy_score, classification_report, confusion_matrix
from sklearn.preprocessing import StandardScaler

# 加载Iris数据集
# iris = load_iris()
# X = iris.data
# y = iris.target

wine = load_wine()
X = wine.data
y = wine.target

# 划分训练集和测试集
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)

# 数据标准化
scaler = StandardScaler()
X_train_scaled = scaler.fit_transform(X_train)
X_test_scaled = scaler.transform(X_test)

# 构建MLP模型
mlp = MLPClassifier(hidden_layer_sizes=(100,), max_iter=1000, random_state=42)

# 训练模型
mlp.fit(X_train_scaled, y_train)

# 在测试集上进行预测
y_pred = mlp.predict(X_test_scaled)

# 评估模型性能
accuracy = accuracy_score(y_test, y_pred)
conf_matrix = confusion_matrix(y_test, y_pred)
class_report = classification_report(y_test, y_pred)

# 打印结果
print("Accuracy:", accuracy)
print("\nConfusion Matrix:\n", conf_matrix)
print("\nClassification Report:\n", class_report)

CIFAR-10:

We use the data that comes with tf.keras.datasets.cifar10 for training

Use the tf.keras.Sequential() function to create a model and set up a four-layer network

Then batch train the code, evaluate and retain the model, and visualize the results.

########cifar10数据集##########
###########保存模型############
########卷积神经网络##########
#train_x:(50000, 32, 32, 3), train_y:(50000, 1), test_x:(10000, 32, 32, 3), test_y:(10000, 1)
#60000条训练数据和10000条测试数据，32x32像素的RGB图像
#第一层两个卷积层16个3*3卷积核，一个池化层：最大池化法2*2卷积核，激活函数：ReLU
#第二层两个卷积层32个3*3卷积核，一个池化层：最大池化法2*2卷积核，激活函数：ReLU
#隐含层激活函数：ReLU函数
#输出层激活函数：softmax函数（实现多分类）
#损失函数：稀疏交叉熵损失函数
#隐含层有128个神经元，输出层有10个节点
import tensorflow as tf
import matplotlib.pyplot as plt
import numpy as np

import time
print('--------------')
nowtime = time.strftime('%Y-%m-%d %H:%M:%S')
print(nowtime)

#指定GPU
#import os
#os.environ["CUDA_VISIBLE_DEVICES"] = "0"
# gpus = tf.config.experimental.list_physical_devices('GPU')
# tf.config.experimental.set_memory_growth(gpus[0],True)
#初始化
plt.rcParams['font.sans-serif'] = ['SimHei']

#加载数据
cifar10 = tf.keras.datasets.cifar10
(train_x,train_y),(test_x,test_y) = cifar10.load_data()
print('\n train_x:%s, train_y:%s, test_x:%s, test_y:%s'%(train_x.shape,train_y.shape,test_x.shape,test_y.shape))

#数据预处理
X_train,X_test = tf.cast(train_x/255.0,tf.float32),tf.cast(test_x/255.0,tf.float32)     #归一化
y_train,y_test = tf.cast(train_y,tf.int16),tf.cast(test_y,tf.int16)


#建立模型
model = tf.keras.Sequential()
##特征提取阶段
#第一层
model.add(tf.keras.layers.Conv2D(16,kernel_size=(3,3),padding='same',activation=tf.nn.relu,data_format='channels_last',input_shape=X_train.shape[1:]))  #卷积层，16个卷积核，大小（3，3），保持原图像大小，relu激活函数，输入形状（28，28，1）
model.add(tf.keras.layers.Conv2D(16,kernel_size=(3,3),padding='same',activation=tf.nn.relu))
model.add(tf.keras.layers.MaxPool2D(pool_size=(2,2)))   #池化层，最大值池化，卷积核（2，2）
#第二层
model.add(tf.keras.layers.Conv2D(32,kernel_size=(3,3),padding='same',activation=tf.nn.relu))
model.add(tf.keras.layers.Conv2D(32,kernel_size=(3,3),padding='same',activation=tf.nn.relu))
model.add(tf.keras.layers.MaxPool2D(pool_size=(2,2)))
##分类识别阶段
#第三层
model.add(tf.keras.layers.Flatten())    #改变输入形状
#第四层
model.add(tf.keras.layers.Dense(128,activation='relu'))     #全连接网络层，128个神经元，relu激活函数
model.add(tf.keras.layers.Dense(10,activation='softmax'))   #输出层，10个节点
print(model.summary())      #查看网络结构和参数信息

#配置模型训练方法
#adam算法参数采用keras默认的公开参数，损失函数采用稀疏交叉熵损失函数，准确率采用稀疏分类准确率函数
model.compile(optimizer='adam',loss='sparse_categorical_crossentropy',metrics=['sparse_categorical_accuracy'])

#训练模型
#批量训练大小为64，迭代5次，测试集比例0.2（48000条训练集数据，12000条测试集数据）
print('--------------')
nowtime = time.strftime('%Y-%m-%d %H:%M:%S')
print('训练前时刻：'+str(nowtime))

history = model.fit(X_train,y_train,batch_size=64,epochs=5,validation_split=0.2)

print('--------------')
nowtime = time.strftime('%Y-%m-%d %H:%M:%S')
print('训练后时刻：'+str(nowtime))

#评估模型
model.evaluate(X_test,y_test,verbose=2)     #每次迭代输出一条记录，来评价该模型是否有比较好的泛化能力

#保存整个模型
model.save('CIFAR10_CNN_weights.h5')

#结果可视化
print(history.history)
loss = history.history['loss']          #训练集损失
val_loss = history.history['val_loss']  #测试集损失
acc = history.history['sparse_categorical_accuracy']            #训练集准确率
val_acc = history.history['val_sparse_categorical_accuracy']    #测试集准确率

plt.figure(figsize=(10,3))

plt.subplot(121)
plt.plot(loss,color='b',label='train')
plt.plot(val_loss,color='r',label='test')
plt.ylabel('loss')
plt.legend()

plt.subplot(122)
plt.plot(acc,color='b',label='train')
plt.plot(val_acc,color='r',label='test')
plt.ylabel('Accuracy')
plt.legend()

#暂停5秒关闭画布，否则画布一直打开的同时，会持续占用GPU内存
#根据需要自行选择
#plt.ion()       #打开交互式操作模式
#plt.show()
#plt.pause(5)
#plt.close()

#使用模型
plt.figure()
for i in range(10):
    num = np.random.randint(1,10000)

    plt.subplot(2,5,i+1)
    plt.axis('off')
    plt.imshow(test_x[num],cmap='gray')
    demo = tf.reshape(X_test[num],(1,32,32,3))
    y_pred = np.argmax(model.predict(demo))
    plt.title('标签值：'+str(test_y[num])+'\n预测值：'+str(y_pred))
#y_pred = np.argmax(model.predict(X_test[0:5]),axis=1)
#print('X_test[0:5]: %s'%(X_test[0:5].shape))
#print('y_pred: %s'%(y_pred))

#plt.ion()       #打开交互式操作模式
plt.show()
#plt.pause(5)
#plt.close()

project address

https://gitee.com/yishangyishang/homeword.git