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前言 – 人工智能教程编辑https://www.captainbed.cn/lzxhttps://www.captainbed.cn/lzx
人工智能(Artificial Intelligence, AI)是当前科技发展的前沿领域,广泛应用于各行各业。学习AI需要系统的知识体系和丰富的实践经验。本文将详细介绍AI的学习路线,分点讲解各个部分的具体实例,帮助学习者全面掌握AI技术。
数学是AI的基础,主要包括线性代数、微积分、概率与统计和离散数学。以下是具体实例和详细讲解。
- import numpy as np
-
- # 创建矩阵
- A = np.array([[1, 2], [3, 4]])
- B = np.array([[5, 6], [7, 8]])
-
- # 矩阵加法
- C = A + B
- print("矩阵加法结果:\n", C)
-
- # 矩阵乘法
- D = np.dot(A, B)
- print("矩阵乘法结果:\n", D)
- import sympy as sp
-
- # 定义变量和函数
- x = sp.symbols('x')
- f = x**3 + 2*x**2 + x + 1
-
- # 计算导数
- f_prime = sp.diff(f, x)
- print("函数的导数:", f_prime)
- import numpy as np
- import matplotlib.pyplot as plt
-
- # 生成正态分布数据
- data = np.random.normal(0, 1, 1000)
-
- # 绘制概率分布图
- plt.hist(data, bins=30, density=True)
- plt.title("正态分布")
- plt.xlabel("值")
- plt.ylabel("概率密度")
- plt.show()
- from collections import deque
-
- # 定义图的邻接表
- graph = {
- 'A': ['B', 'C'],
- 'B': ['A', 'D', 'E'],
- 'C': ['A', 'F'],
- 'D': ['B'],
- 'E': ['B', 'F'],
- 'F': ['C', 'E']
- }
-
- # 广度优先搜索算法
- def bfs(graph, start):
- visited = set()
- queue = deque([start])
-
- while queue:
- vertex = queue.popleft()
- if vertex not in visited:
- print(vertex, end=" ")
- visited.add(vertex)
- queue.extend(set(graph[vertex]) - visited)
-
- # 执行广度优先搜索
- bfs(graph, 'A')
计算机科学的基本知识是AI学习的前提,主要包括编程语言、数据结构和算法、计算机体系结构。
- from sklearn.datasets import load_iris
- from sklearn.model_selection import train_test_split
- from sklearn.linear_model import LogisticRegression
- from sklearn.metrics import accuracy_score
-
- # 加载数据集
- iris = load_iris()
- X, y = iris.data, iris.target
-
- # 数据集划分
- X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)
-
- # 模型训练
- model = LogisticRegression(max_iter=200)
- model.fit(X_train, y_train)
-
- # 模型预测
- y_pred = model.predict(X_test)
-
- # 模型评估
- accuracy = accuracy_score(y_test, y_pred)
- print("模型准确率:", accuracy)
重点概念:
- def quicksort(arr):
- if len(arr) <= 1:
- return arr
- pivot = arr[len(arr) // 2]
- left = [x for x in arr if x < pivot]
- middle = [x for x in arr if x == pivot]
- right = [x for x in arr if x > pivot]
- return quicksort(left) + middle + quicksort(right)
-
- # 测试快速排序算法
- arr = [3, 6, 8, 10, 1, 2, 1]
- print("排序结果:", quicksort(arr))
重点概念:
- import numpy as np
- from numba import cuda
-
- # 定义CUDA内核函数
- @cuda.jit
- def add_arrays(a, b, c):
- idx = cuda.grid(1)
- if idx < a.size:
- c[idx] = a[idx] + b[idx]
-
- # 创建数据
- N = 100000
- a = np.ones(N, dtype=np.float32)
- b = np.ones(N, dtype=np.float32)
- c = np.zeros(N, dtype=np.float32)
-
- # 分配设备内存
- a_device = cuda.to_device(a)
- b_device = cuda.to_device(b)
- c_device = cuda.device_array_like(c)
-
- # 配置块和网格
- threads_per_block = 256
- blocks_per_grid = (a.size + (threads_per_block - 1)) // threads_per_block
-
- # 启动内核
- add_arrays[blocks_per_grid, threads_per_block](a_device, b_device, c_device)
-
- # 复制结果回主机
- c = c_device.copy_to_host()
- print("计算结果:", c[:10]) # 显示前10个结果
重点概念:
机器学习是AI的核心,涉及监督学习、无监督学习和强化学习。
- from sklearn.datasets import load_iris
- from sklearn.model_selection import train_test_split
- from sklearn.neighbors import KNeighborsClassifier
- from sklearn.metrics import accuracy_score
-
- # 加载数据集
- iris = load_iris()
- X, y = iris.data, iris.target
-
- # 数据集划分
- X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)
-
- # 模型训练
- knn = KNeighborsClassifier(n_neighbors=3)
- knn.fit(X_train, y_train)
-
- # 模型预测
- y_pred = knn.predict(X_test)
-
- # 模型评估
- accuracy = accuracy_score(y_test, y_pred)
- print("KNN模型准确率:", accuracy)
重点概念:
- import numpy as np
- from sklearn.cluster import KMeans
- import matplotlib.pyplot as plt
-
- # 生成数据
- X = np.array([[1, 2], [1, 4], [1, 0],
- [4, 2], [4, 4], [4, 0]])
-
- # 模型训练
- kmeans = KMeans(n_clusters=2, random_state=0).fit(X)
-
- # 预测聚类结果
- labels = kmeans.labels_
- print("K均值聚类结果:", labels)
-
- # 可视化聚类结果
- plt.scatter(X[:, 0], X[:, 1], c=labels, cmap='viridis')
- plt.scatter(kmeans.cluster_centers_[:, 0], kmeans.cluster_centers_[:, 1], s=300, c='red')
- plt.show()
重点概念:
- import numpy as np
- import random
-
- # 环境定义
- states = ["A", "B", "C", "D", "E", "F"]
- actions = ["left", "right"]
- rewards = {
- "A": {"left": 0, "right": 0},
- "B": {"left": 0, "right": 1},
- "C": {"left": 0, "right": 0},
- "D": {"left": 1, "right": 0},
- "E": {"left": 0, "right": 0},
- "F": {"left": 0, "right": 0}
- }
- Q = {}
-
- # 初始化Q表
- for state in states:
- Q[state] = {}
- for action in actions:
- Q[state][action] = 0
-
- # Q学习算法
- alpha = 0.1 # 学习率
- gamma = 0.9 # 折扣因子
- epsilon = 0.1 # 探索率
-
- def choose_action(state):
- if random.uniform(0, 1) < epsilon:
- return random.choice(actions)
- else:
- return max(Q[state], key=Q[state].get)
-
- def update_q(state, action, reward, next_state):
- predict = Q[state][action]
- target = reward + gamma * max(Q[next_state].values())
- Q[state][action] += alpha * (target - predict)
-
- # 训练Q表
- episodes = 1000
- for _ in range(episodes):
- state = random.choice(states)
- while state != "F":
- action = choose_action(state)
- reward = rewards[state][action]
- next_state = "F" if action == "right" else state
- update_q(state, action, reward, next_state)
- state = next_state
-
- print("Q表:", Q)
深度学习是机器学习的一个重要分支,涉及神经网络的训练和优化。
- import numpy as np
- from keras.models import Sequential
- from keras.layers import Dense
- from sklearn.datasets import load_iris
- from sklearn.model_selection import train_test_split
- from sklearn.preprocessing import OneHotEncoder
-
- # 加载数据集
- iris = load_iris()
- X, y = iris.data, iris.target
-
- # 独热编码标签
- encoder = OneHotEncoder(sparse=False)
- y = encoder.fit_transform(y.reshape(-1, 1))
-
- # 数据集划分
- X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)
-
- # 创建模型
- model = Sequential()
- model.add(Dense(10, input_dim=4, activation='relu'))
- model.add(Dense(10, activation='relu'))
- model.add(Dense(3, activation='softmax'))
-
- # 编译模型
- model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
-
- # 训练模型
- model.fit(X_train, y_train, epochs=100, batch_size=10)
-
- # 评估模型
- _, accuracy = model.evaluate(X_test, y_test)
- print("神经网络模型准确率:", accuracy)
- from keras.datasets import mnist
- from keras.utils import np_utils
- from keras.models import Sequential
- from keras.layers import Conv2D, MaxPooling2D, Flatten, Dense
-
- # 加载数据集
- (X_train, y_train), (X_test, y_test) = mnist.load_data()
-
- # 数据预处理
- X_train = X_train.reshape(X_train.shape[0], 28, 28, 1).astype('float32') / 255
- X_test = X_test.reshape(X_test.shape[0], 28, 28, 1).astype('float32') / 255
- y_train = np_utils.to_categorical(y_train)
- y_test = np_utils.to_categorical(y_test)
-
- # 创建模型
- model = Sequential()
- model.add(Conv2D(32, (5, 5), input_shape=(28, 28, 1), activation='relu'))
- model.add(MaxPooling2D(pool_size=(2, 2)))
- model.add(Conv2D(64, (5, 5), activation='relu'))
- model.add(MaxPooling2D(pool_size=(2, 2)))
- model.add(Flatten())
- model.add(Dense(1000, activation='relu'))
- model.add(Dense(10, activation='softmax'))
-
- # 编译模型
- model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
-
- # 训练模型
- model.fit(X_train, y_train, validation_data=(X_test, y_test), epochs=10, batch_size=200)
-
- # 评估模型
- _, accuracy = model.evaluate(X_test, y_test)
- print("CNN模型准确率:", accuracy)
- from keras.preprocessing.text import Tokenizer
- from keras.preprocessing.sequence import pad_sequences
- from keras.models import Sequential
- from keras.layers import Embedding, LSTM, Dense
- from sklearn.model_selection import train_test_split
- import numpy as np
-
- # 样本数据
- texts = ['I love machine learning', 'Deep learning is awesome', 'I hate spam emails']
- labels = [1, 1, 0]
-
- # 文本预处理
- tokenizer = Tokenizer(num_words=10000)
- tokenizer.fit_on_texts(texts)
- sequences = tokenizer.texts_to_sequences(texts)
- X = pad_sequences(sequences, maxlen=10)
- y = np.array(labels)
-
- # 数据集划分
- X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)
-
- # 创建模型
- model = Sequential()
- model.add(Embedding(10000, 128, input_length=10))
- model.add(LSTM(128))
- model.add(Dense(1, activation='sigmoid'))
-
- # 编译模型
- model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])
-
- # 训练模型
- model.fit(X_train, y_train, epochs=10, batch_size=32)
-
- # 评估模型
- _, accuracy = model.evaluate(X_test, y_test)
- print("LSTM模型准确率:", accuracy)
- import numpy as np
- from keras.models import Sequential
- from keras.layers import Dense
- from keras.optimizers import Adam
-
- # 生成器模型
- def build_generator():
- model = Sequential()
- model.add(Dense(256, input_dim=100, activation='relu'))
- model.add(Dense(512, activation='relu'))
- model.add(Dense(1024, activation='relu'))
- model.add(Dense(28*28, activation='tanh'))
- model.compile(loss='binary_crossentropy', optimizer=Adam(0.0002, 0.5))
- return model
-
- # 判别器模型
- def build_discriminator():
- model = Sequential()
- model.add(Dense(1024, input_dim=28*28, activation='relu'))
- model.add(Dense(512, activation='relu'))
- model.add(Dense(256, activation='relu'))
- model.add(Dense(1, activation='sigmoid'))
- model.compile(loss='binary_crossentropy', optimizer=Adam(0.0002, 0.5))
- return model
-
- # 构建GAN模型
- def build_gan(generator, discriminator):
- discriminator.trainable = False
- model = Sequential()
- model.add(generator)
- model.add(discriminator)
- model.compile(loss='binary_crossentropy', optimizer=Adam(0.0002, 0.5))
- return model
-
- # 初始化模型
- generator = build_generator()
- discriminator = build_discriminator()
- gan = build_gan(generator, discriminator)
-
- # 训练GAN模型
- def train_gan(epochs, batch_size):
- (X_train, _), (_, _) = mnist.load_data()
- X_train = (X_train.astype(np.float32) - 127.5) / 127.5
- X_train = X_train.reshape(X_train.shape[0], 28*28)
-
- for epoch in range(epochs):
- idx = np.random.randint(0, X_train.shape[0], batch_size)
- real_imgs = X_train[idx]
-
- noise = np.random.normal(0, 1, (batch_size, 100))
- fake_imgs = generator.predict(noise)
-
- d_loss_real = discriminator.train_on_batch(real_imgs, np.ones((batch_size, 1)))
- d_loss_fake = discriminator.train_on_batch(fake_imgs, np.zeros((batch_size, 1)))
- d_loss = 0.5 * np.add(d_loss_real, d_loss_fake)
-
- noise = np.random.normal(0, 1, (batch_size, 100))
- g_loss = gan.train_on_batch(noise, np.ones((batch_size, 1)))
-
- if epoch % 1000 == 0:
- print(f"{epoch} [D loss: {d_loss}] [G loss: {g_loss}]")
-
- # 开始训练
- train_gan(epochs=10000, batch_size=64)
重点概念:
应用:图像生成、风格迁移
NLP是AI的重要应用领域,涉及文本预处理、语言模型和具体应用。
- from nltk.tokenize import word_tokenize
- from nltk.corpus import stopwords
- from nltk.stem import PorterStemmer
- import string
-
- # 示例文本
- text = "I love natural language processing. It's fascinating!"
-
- # 分词
- words = word_tokenize(text)
-
- # 去除停用词
- stop_words = set(stopwords.words('english'))
- words = [word for word in words if word.lower() not in stop_words]
-
- # 去除标点符号
- words = [word for word in words if word not in string.punctuation]
-
- # 词干化
- ps = PorterStemmer()
- words = [ps.stem(word) for word in words]
-
- print("预处理后的文本:", words)
- from transformers import GPT2LMHeadModel, GPT2Tokenizer
-
- # 加载模型和分词器
- model_name = "gpt2"
- model = GPT2LMHeadModel.from_pretrained(model_name)
- tokenizer = GPT2Tokenizer.from_pretrained(model_name)
-
- # 输入文本
- input_text = "Once upon a time"
- input_ids = tokenizer.encode(input_text, return_tensors='pt')
-
- # 生成文本
- output = model.generate(input_ids, max_length=50, num_return_sequences=1)
- output_text = tokenizer.decode(output[0], skip_special_tokens=True)
-
- print("生成的文本:", output_text)
- from textblob import TextBlob
-
- # 示例文本
- text = "I love this product! It's amazing."
-
- # 情感分析
- blob = TextBlob(text)
- sentiment = blob.sentiment
-
- print("情感分析结果:", sentiment)
重点概念:
数据是AI模型训练的基础,涉及数据采集、数据清洗和数据增强。
- import requests
- from bs4 import BeautifulSoup
-
- # 目标URL
- url = "https://example.com"
-
- # 发起请求
- response = requests.get(url)
-
- # 解析HTML内容
- soup = BeautifulSoup(response.content, 'html.parser')
-
- # 提取数据
- titles = soup.find_all('h2')
- for title in titles:
- print("标题:", title.text)
- import pandas as pd
-
- # 示例数据
- data = {
- 'name': ['Alice', 'Bob', 'Charlie', 'David', 'Eve'],
- 'age': [24, 27, 22, 32, 29],
- 'city': ['New York', 'San Francisco', 'Los Angeles', None, 'Chicago']
- }
- df = pd.DataFrame(data)
-
- # 缺失值处理
- df['city'].fillna('Unknown', inplace=True)
-
- # 数据规范化
- df['age'] = (df['age'] - df['age'].mean()) / df['age'].std()
-
- print("清洗后的数据:\n", df)
- from keras.preprocessing.image import ImageDataGenerator
- import matplotlib.pyplot as plt
- from keras.datasets import mnist
-
- # 加载数据集
- (X_train, y_train), (_, _) = mnist.load_data()
- X_train = X_train.reshape(X_train.shape[0], 28, 28, 1).astype('float32')
-
- # 数据增强
- datagen = ImageDataGenerator(
- rotation_range=10,
- zoom_range=0.1,
- width_shift_range=0.1,
- height_shift_range=0.1
- )
- datagen.fit(X_train)
-
- # 显示增强后的图像
- for X_batch, y_batch in datagen.flow(X_train, y_train, batch_size=9):
- for i in range(0, 9):
- plt.subplot(330 + 1 + i)
- plt.imshow(X_batch[i].reshape(28, 28), cmap=plt.get_cmap('gray'))
- plt.show()
- break
重点概念:
模型训练
模型的训练和优化是AI开发的重要环节。
- from sklearn.datasets import load_iris
- from sklearn.model_selection import train_test_split
- from sklearn.ensemble import RandomForestClassifier
- from sklearn.metrics import accuracy_score
-
- # 加载数据集
- iris = load_iris()
- X, y = iris.data, iris.target
-
- # 数据集划分
- X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)
-
- # 模型训练
- model = RandomForestClassifier(n_estimators=100)
- model.fit(X_train, y_train)
-
- # 模型预测
- y_pred = model.predict(X_test)
-
- # 模型评估
- accuracy = accuracy_score(y_test, y_pred)
- print("随机森林模型准确率:", accuracy)
- from keras.models import Sequential
- from keras.layers import Dense, Dropout
- from keras.optimizers import Adam
-
- # 创建模型
- model = Sequential()
- model.add(Dense(64, input_dim=20, activation='relu'))
- model.add(Dropout(0.5))
- model.add(Dense(64, activation='relu'))
- model.add(Dropout(0.5))
- model.add(Dense(1, activation='sigmoid'))
-
- # 编译模型
- model.compile(loss='binary_crossentropy', optimizer=Adam(lr=0.001), metrics=['accuracy'])
-
- # 训练模型
- model.fit(X_train, y_train, epochs=50, batch_size=32, validation_split=0.2)
- from flask import Flask, request, jsonify
- import pickle
-
- # 加载模型
- model = pickle.load(open('model.pkl', 'rb'))
-
- # 创建Flask应用
- app = Flask(__name__)
-
- # 定义预测接口
- @app.route('/predict', methods=['POST'])
- def predict():
- data = request.get_json(force=True)
- prediction = model.predict([data['features']])
- output = {'prediction': int(prediction[0])}
- return jsonify(output)
-
- # 启动应用
- if __name__ == '__main__':
- app.run(debug=True)
图像分类
通过实战项目可以巩固所学知识并积累经验。
- from keras.datasets import cifar10
- from keras.models import Sequential
- from keras.layers import Conv2D, MaxPooling2D, Flatten, Dense
- from keras.utils import np_utils
-
- # 加载数据集
- (X_train, y_train), (X_test, y_test) = cifar10.load_data()
-
- # 数据预处理
- X_train = X_train.astype('float32') / 255
- X_test = X_test.astype('float32') / 255
- y_train = np_utils.to_categorical(y_train, 10)
- y_test = np_utils.to_categorical(y_test, 10)
-
- # 创建模型
- model = Sequential()
- model.add(Conv2D(32, (3, 3), input_shape=(32, 32, 3), activation='relu'))
- model.add(MaxPooling2D(pool_size=(2, 2)))
- model.add(Conv2D(64, (3, 3), activation='relu'))
- model.add(MaxPooling2D(pool_size=(2, 2)))
- model.add(Flatten())
- model.add(Dense(512, activation='relu'))
- model.add(Dense(10, activation='softmax'))
-
- # 编译模型
- model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
-
- # 训练模型
- model.fit(X_train, y_train, validation_data=(X_test, y_test), epochs=10, batch_size=64)
-
- # 评估模型
- _, accuracy = model.evaluate(X_test, y_test)
- print("CIFAR-10图像分类模型准确率:", accuracy)
重点概念:
- from transformers import BertTokenizer, BertForSequenceClassification
- from transformers import Trainer, TrainingArguments
- from sklearn.model_selection import train_test_split
- import torch
-
- # 示例数据
- texts = ["I love AI", "AI is the future", "I hate spam emails"]
- labels = [1, 1, 0]
-
- # 加载预训练模型和分词器
- model_name = "bert-base-uncased"
- tokenizer = BertTokenizer.from_pretrained(model_name)
- model = BertForSequenceClassification.from_pretrained(model_name, num_labels=2)
-
- # 数据预处理
- inputs = tokenizer(texts, return_tensors="pt", padding=True, truncation=True)
- inputs['labels'] = torch.tensor(labels)
-
- # 数据集划分
- train_inputs, val_inputs, train_labels, val_labels = train_test_split(inputs['input_ids'], inputs['labels'], test_size=0.3, random_state=42)
-
- # 创建数据集
- train_dataset = torch.utils.data.TensorDataset(train_inputs, train_labels)
- val_dataset = torch.utils.data.TensorDataset(val_inputs, val_labels)
-
- # 设置训练参数
- training_args = TrainingArguments(output_dir='./results', num_train_epochs=3, per_device_train_batch_size=16, per_device_eval_batch_size=16, warmup_steps=500, weight_decay=0.01, logging_dir='./logs')
-
- # 创建Trainer
- trainer = Trainer(model=model, args=training_args, train_dataset=train_dataset, eval_dataset=val_dataset)
-
- # 训练模型
- trainer.train()
- import gym
- import numpy as np
-
- # 创建环境
- env = gym.make('CartPole-v1')
-
- # Q学习算法
- Q = np.zeros((env.observation_space.shape[0], env.action_space.n))
- alpha = 0.1 # 学习率
- gamma = 0.99 # 折扣因子
- epsilon = 0.1 # 探索率
-
- def choose_action(state):
- if np.random.uniform(0, 1) < epsilon:
- return env.action_space.sample()
- else:
- return np.argmax(Q[state, :])
-
- def update_q(state, action, reward, next_state):
- predict = Q[state, action]
- target = reward + gamma * np.max(Q[next_state, :])
- Q[state, action] += alpha * (target - predict)
-
- # 训练Q表
- episodes = 1000
- for _ in range(episodes):
- state = env.reset()
- done = False
- while not done:
- action = choose_action(state)
- next_state, reward, done, _ = env.step(action)
- update_q(state, action, reward, next_state)
- state = next_state
-
- print("Q表:", Q)
AI领域不断涌现新技术,学习者需要保持学习的热情和动力。
- import numpy as np
-
- # 模拟本地数据
- def generate_data(size):
- X = np.random.rand(size, 10)
- y = (np.sum(X, axis=1) > 5).astype(int)
- return X, y
-
- # 本地模型训练
- def train_local_model(X, y):
- model = LogisticRegression()
- model.fit(X, y)
- return model.coef_, model.intercept_
-
- # 模拟客户端数据
- clients = 5
- local_models = []
- for _ in range(clients):
- X, y = generate_data(100)
- coef, intercept = train_local_model(X, y)
- local_models.append((coef, intercept))
-
- # 聚合模型参数
- global_coef = np.mean([model[0] for model in local_models], axis=0)
- global_intercept = np.mean([model[1] for model in local_models], axis=0)
-
- print("全局模型参数:", global_coef, global_intercept)
- from torchvision import datasets, transforms, models
- from torch.utils.data import DataLoader
- import torch
- import torch.nn as nn
- import torch.optim as optim
-
- # 数据预处理
- transform = transforms.Compose([transforms.ToTensor(), transforms.Normalize((0.5,), (0.5,))])
- dataset = datasets.MNIST(root='./data', train=True, download=True, transform=transform)
- dataloader = DataLoader(dataset, batch_size=64, shuffle=True)
-
- # 定义自监督学习模型
- class Autoencoder(nn.Module):
- def __init__(self):
- super(Autoencoder, self).__init__()
- self.encoder = nn.Sequential(nn.Linear(28*28, 128), nn.ReLU(), nn.Linear(128, 64))
- self.decoder = nn.Sequential(nn.Linear(64, 128), nn.ReLU(), nn.Linear(128, 28*28))
-
- def forward(self, x):
- x = x.view(-1, 28*28)
- encoded = self.encoder(x)
- decoded = self.decoder(encoded)
- return decoded.view(-1, 1, 28, 28)
-
- # 初始化模型、损失函数和优化器
- model = Autoencoder()
- criterion = nn.MSELoss()
- optimizer = optim.Adam(model.parameters(), lr=0.001)
-
- # 训练模型
- epochs = 5
- for epoch in range(epochs):
- for data in dataloader:
- inputs, _ = data
- optimizer.zero_grad()
- outputs = model(inputs)
- loss = criterion(outputs, inputs)
- loss.backward()
- optimizer.step()
- print(f"Epoch [{epoch+1}/{epochs}], Loss: {loss.item():.4f}")
- import numpy as np
- from sklearn.datasets import load_iris
- from sklearn.ensemble import RandomForestClassifier
- import lime
- import lime.lime_tabular
-
- # 加载数据集
- iris = load_iris()
- X, y = iris.data, iris.target
-
- # 模型训练
- model = RandomForestClassifier(n_estimators=100)
- model.fit(X, y)
-
- # 使用LIME解释模型
- explainer = lime.lime_tabular.LimeTabularExplainer(X, feature_names=iris.feature_names, class_names=iris.target_names, discretize_continuous=True)
- i = 25
- exp = explainer.explain_instance(X[i], model.predict_proba, num_features=2, top_labels=1)
- exp.show_in_notebook(show_all=False)
结合具体领域知识,AI可以有更多的应用场景。
- import numpy as np
- from keras.models import Sequential
- from keras.layers import Conv2D, MaxPooling2D, Flatten, Dense
- from keras.preprocessing.image import ImageDataGenerator
-
- # 创建模型
- model = Sequential()
- model.add(Conv2D(32, (3, 3), input_shape=(64, 64, 3), activation='relu'))
- model.add(MaxPooling2D(pool_size=(2, 2)))
- model.add(Conv2D(64, (3, 3), activation='relu'))
- model.add(MaxPooling2D(pool_size=(2, 2)))
- model.add(Flatten())
- model.add(Dense(128, activation='relu'))
- model.add(Dense(1, activation='sigmoid'))
-
- # 编译模型
- model.compile(loss='binary_crossentropy', optimizer='adam', metrics=['accuracy'])
-
- # 数据增强
- train_datagen = ImageDataGenerator(rescale=1./255, shear_range=0.2, zoom_range=0.2, horizontal_flip=True)
- test_datagen = ImageDataGenerator(rescale=1./255)
-
- # 加载训练数据
- training_set = train_datagen.flow_from_directory('dataset/training_set', target_size=(64, 64), batch_size=32, class_mode='binary')
- test_set = test_datagen.flow_from_directory('dataset/test_set', target_size=(64, 64), batch_size=32, class_mode='binary')
-
- # 训练模型
- model.fit(training_set, steps_per_epoch=8000, epochs=25, validation_data=test_set, validation_steps=2000)
重点概念:
- import pandas as pd
- from sklearn.model_selection import train_test_split
- from sklearn.linear_model import LogisticRegression
- from sklearn.metrics import roc_auc_score
-
- # 加载数据集
- data = pd.read_csv('credit_data.csv')
- X = data.drop('default', axis=1)
- y = data['default']
-
- # 数据集划分
- X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)
-
- # 模型训练
- model = LogisticRegression()
- model.fit(X_train, y_train)
-
- # 模型预测
- y_pred_prob = model.predict_proba(X_test)[:, 1]
-
- # 模型评估
- auc = roc_auc_score(y_test, y_pred_prob)
- print("信用评分模型AUC:", auc)
- import pandas as pd
- from sklearn.ensemble import RandomForestClassifier
- from sklearn.model_selection import train_test_split
- from sklearn.metrics import accuracy_score
-
- # 加载数据集
- data = pd.read_csv('equipment_data.csv')
- X = data.drop('failure', axis=1)
- y = data['failure']
-
- # 数据集划分
- X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)
-
- # 模型训练
- model = RandomForestClassifier(n_estimators=100)
- model.fit(X_train, y_train)
-
- # 模型预测
- y_pred = model.predict(X_test)
-
- # 模型评估
- accuracy = accuracy_score(y_test, y_pred)
- print("设备故障预测模型准确率:", accuracy)
重点概念:
以下是一些高质量的在线课程:
Coursera
edX
Udacity
TensorFlow
PyTorch
scikit-learn
人工智能的系统学习路线,从数学基础、计算机基础,到核心技术和实践应用,再到前沿技术和具体领域的深度学习,涵盖了AI学习的各个方面。通过具体实例和详尽讲解,帮助学习者系统掌握AI知识,积累实践经验,并提供了高质量的学习资源和工具,旨在培养出在AI领域中具备领先优势的专业人才。
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