掌握PHP7编程艺术：实例丰富教程指南

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"《Learning PHP 7》是一本由Antonio Lopez编写的实用指南，旨在帮助读者掌握PHP编程的艺术。这本书以丰富的实例和教程为主，包含了每个PHP开发者都应了解的关键技能。它适合于PHP新手和进阶开发者，无论你是初次接触PHP语言，还是希望提升到PHP 7的新版本技术，本书都是不可或缺的参考资料。 该书版权由Packt Publishing持有，所有内容未经许可不得复制、存储或传输，除非用于学术引用。作者和出版商对于书中信息的准确性尽力确保，但不承担因信息错误导致的直接或间接损失的责任。读者在使用本书时应自行判断，因为书中的信息是按当时知识水平提供的，可能无法涵盖所有最新变化。 首次出版日期为2016年3月，体现了作者对PHP 7版本的深入理解，这包括了PHP 7所带来的新特性、改进和性能优化，如更严格的类型系统、更高效的内存管理以及对HTTP/2协议的支持等。书中涵盖了PHP的基本概念，如变量、数据类型、流程控制、函数、类和对象，以及数据库操作、文件处理、表单验证等内容，这些都是构建现代Web应用的核心元素。 通过阅读《Learning PHP 7》，读者可以掌握编写高效、安全且可维护的PHP代码的基础，并能跟随作者的脚步，逐步提升自己的编程技巧和项目开发能力。无论是在个人学习还是职业发展过程中，这本书都提供了宝贵的实践经验和理论指导，是PHP开发者书架上的一部经典之作。"

Mastering PHP 7(pdf+epub+mobi+code_files).zip

2018-07-18 上传
Mastering PHP 7(pdf+epub+mobi+code_files).zip Mastering PHP 7(pdf+epub+mobi+code_files).zip

self.learning_rate = config.learning_rate self.learning_rates = [self.learning_rate, self.learning_rate * 0.5, self.learning_rate * 0.1] self.learning_rate_boundaries = [50000, 75000] self.max_iter = 10000 self.test_iter = 5000 self.disp_iter = 100 self.snapshot_iter = 5000 self.test_initialization = False self.reg_constant = 0.0 self.data_format = 'channels_first' self.network_parameters = OrderedDict(num_filters_base=config.num_filters_base, activation=config.activation, dropout_ratio=config.dropout_ratio, num_levels=config.num_levels, heatmap_initialization=True, data_format=self.data_format)

2023-07-09 上传
- self.learning_rates：学习率列表，根据self.learning_rate计算得到，包括三个值，分别为self.learning_rate、self.learning_rate * 0.5、self.learning_rate * 0.1。 - self.learning_rate_boundaries：学习率...

分析代码 def backward(self, X, y, learning_rate): error = self.y_hat - y error_array = error.values error_flat = error_array.ravel() delta2 = error_flat delta1 = np.dot(delta2_flat, self.weights2.T) * self.relu_derivative(self.a1) grad_weights2 = np.dot(self.a1.T, delta2) grad_bias2 = np.sum(delta2, axis=0, keepdims=True) grad_weights1 = np.dot(X.T, delta1) grad_bias1 = np.sum(delta1, axis=0) self.weights2 -= learning_rate * grad_weights2 self.bias2 -= learning_rate * grad_bias2 self.weights1 -= learning_rate * grad_weights1

2023-06-09 上传
7. `grad_bias2 = np.sum(delta2, axis=0, keepdims=True)`：计算输出层偏差的梯度。 8. `grad_weights1 = np.dot(X.T, delta1)`：计算隐藏层权重的梯度。 9. `grad_bias1 = np.sum(delta1, axis=0)`：计算隐藏层...

def __init__(self, sess, state_dim, learning_rate): self.sess = sess self.s_dim = state_dim self.lr_rate = learning_rate # Create the critic network self.inputs, self.out = self.create_critic_network() # Get all network parameters self.network_params = \ tf.compat.v1.get_collection(tf.compat.v1.GraphKeys.TRAINABLE_VARIABLES, scope='critic') # Set all network parameters self.input_network_params = [] for param in self.network_params: self.input_network_params.append( tf.compat.v1.placeholder(tf.float32, shape=param.get_shape())) self.set_network_params_op = [] for idx, param in enumerate(self.input_network_params): self.set_network_params_op.append(self.network_params[idx].assign(param)) # Network target目标 V(s) self.td_target = tf.compat.v1.placeholder(tf.float32, [None, 1]) # Temporal Difference, will also be weights for actor_gradients时间差异，也将是actor_gradients的权重 self.td = tf.subtract(self.td_target, self.out) # Mean square error均方误差 self.loss = tflearn.mean_square(self.td_target, self.out) # Compute critic gradient计算临界梯度 self.critic_gradients = tf.gradients(self.loss, self.network_params) # Optimization Op self.optimize = tf.compat.v1.train.RMSPropOptimizer(self.lr_rate). \ apply_gradients(zip(self.critic_gradients, self.network_params))请对这段代码每句进行注释

2023-05-14 上传
def __init__(self, sess, state_dim, learning_rate): # 初始化 Critic 网络的一些参数 self.sess = sess self.s_dim = state_dim self.lr_rate = learning_rate # 创建 Critic 网络 self.inputs, self....

class NeuralNetwork: def __init__(self, input_dim, hidden_dim, output_dim): self.input_dim = input_dim self.hidden_dim = hidden_dim self.output_dim = output_dim self.weights1 = np.random.randn(input_dim, hidden_dim) self.bias1 = np.zeros((1, hidden_dim)) self.weights2 = np.random.randn(hidden_dim, output_dim) self.bias2 = np.zeros((1, output_dim)) def relu(self, x): return np.maximum(0, x) def relu_derivative(self, x): return np.where(x >= 0, 1, 0) def forward(self, x): self.z1 = np.dot(x, self.weights1) + self.bias1 self.a1 = self.relu(self.z1) self.z2 = np.dot(self.a1, self.weights2) + self.bias2 self.y_hat = self.z2 return self.y_hat def backward(self, x, y, learning_rate): error = self.y_hat - y delta2 = error delta1 = np.dot(delta2, self.weights2.T) * self.relu_derivative(self.a1) grad_weights2 = np.dot(self.a1.T, delta2) grad_bias2 = np.sum(delta2, axis=0, keepdims=True) grad_weights1 = np.dot(x.T, delta1) grad_bias1 = np.sum(delta1, axis=0) self.weights2 -= learning_rate * grad_weights2 self.bias2 -= learning_rate * grad_bias2 self.weights1 -= learning_rate * grad_weights1 根据代码加上损失函数

2023-06-08 上传
def backward(self, x, y, learning_rate): error = self.y_hat - y delta2 = self.mse_loss_derivative(y) * self.relu_derivative(self.z2) # 加上损失函数的导数 delta1 = np.dot(delta2, self.weights2.T) * ...

解释一下这段代码% Set conjugate gradient uptions init_CG_opts.CG_use_FR = true; init_CG_opts.tol = 1e-6; init_CG_opts.CG_standard_alpha = true; init_CG_opts.debug = params.debug; CG_opts.CG_use_FR = params.CG_use_FR; CG_opts.tol = 1e-6; CG_opts.CG_standard_alpha = params.CG_standard_alpha; CG_opts.debug = params.debug; if params.CG_forgetting_rate == Inf || params.learning_rate >= 1 CG_opts.init_forget_factor = 0; else CG_opts.init_forget_factor = (1-params.learning_rate)^params.CG_forgetting_rate; end seq.time = 0;

2023-07-23 上传
如果 `params.CG_forgetting_rate` 等于正无穷或 `params.learning_rate` 大于等于1，则将 `CG_opts.init_forget_factor` 设置为0；否则，根据公式 `(1-params.learning_rate)^params.CG_forgetting_rate` 计算并...

以下这段代码是关于CatBoost模型的超参数调整，但里面好像不是在五倍交叉验证下做的分析，请问应该怎么加上五倍交叉验证呢？import os import time import pandas as pd from catboost import CatBoostRegressor from hyperopt import fmin, hp, partial, Trials, tpe,rand from sklearn.metrics import r2_score, mean_squared_error from sklearn.model_selection import train_test_split from sklearn.model_selection import KFold, cross_val_score as CVS, train_test_split as TTS 自定义hyperopt的参数空间 space = {"iterations": hp.choice("iterations", range(1, 30)), "depth": hp.randint("depth", 16), "l2_leaf_reg": hp.randint("l2_leaf_reg", 222), "border_count": hp.randint("border_count", 222), 'learning_rate': hp.uniform('learning_rate', 0.001, 0.9), } data = pd.read_csv(r"E:\exercise\synthesis\synthesis_dummy_2.csv") #验证随机森林填补缺失值方法是否有效 X = data.iloc[:,1:] y = data.iloc[:,0] Xtrain,Xtest,Ytrain,Ytest = TTS(X_wrapper,y,test_size=0.2,random_state=100) def epoch_time(start_time, end_time): elapsed_secs = end_time - start_time elapsed_mins = elapsed_secs / 60 return elapsed_mins, elapsed_secs 自动化调参并训练 def cat_factory(argsDict): estimator = CatBoostRegressor(loss_function='RMSE', random_seed=22, learning_rate=argsDict['learning_rate'], iterations=argsDict['iterations'], l2_leaf_reg=argsDict['l2_leaf_reg'], border_count=argsDict['border_count'], depth=argsDict['depth'], verbose=0) estimator.fit(Xtrain, Ytrain) val_pred = estimator.predict(Xtest) mse = mean_squared_error(Ytest, val_pred) return mse

2023-07-20 上传
learning_rate=argsDict['learning_rate'], iterations=argsDict['iterations'], l2_leaf_reg=argsDict['l2_leaf_reg'], border_count=argsDict['border_count'], depth=argsDict['depth'], verbose=0) # ...

运行以下Python代码：import torchimport torch.nn as nnimport torch.optim as optimfrom torchvision import datasets, transformsfrom torch.utils.data import DataLoaderfrom torch.autograd import Variableclass Generator(nn.Module): def __init__(self, input_dim, output_dim, num_filters): super(Generator, self).__init__() self.input_dim = input_dim self.output_dim = output_dim self.num_filters = num_filters self.net = nn.Sequential( nn.Linear(input_dim, num_filters), nn.ReLU(), nn.Linear(num_filters, num_filters*2), nn.ReLU(), nn.Linear(num_filters*2, num_filters*4), nn.ReLU(), nn.Linear(num_filters*4, output_dim), nn.Tanh() ) def forward(self, x): x = self.net(x) return xclass Discriminator(nn.Module): def __init__(self, input_dim, num_filters): super(Discriminator, self).__init__() self.input_dim = input_dim self.num_filters = num_filters self.net = nn.Sequential( nn.Linear(input_dim, num_filters*4), nn.LeakyReLU(0.2), nn.Linear(num_filters*4, num_filters*2), nn.LeakyReLU(0.2), nn.Linear(num_filters*2, num_filters), nn.LeakyReLU(0.2), nn.Linear(num_filters, 1), nn.Sigmoid() ) def forward(self, x): x = self.net(x) return xclass ConditionalGAN(object): def __init__(self, input_dim, output_dim, num_filters, learning_rate): self.generator = Generator(input_dim, output_dim, num_filters) self.discriminator = Discriminator(input_dim+1, num_filters) self.optimizer_G = optim.Adam(self.generator.parameters(), lr=learning_rate) self.optimizer_D = optim.Adam(self.discriminator.parameters(), lr=learning_rate) def train(self, data_loader, num_epochs): for epoch in range(num_epochs): for i, (inputs, labels) in enumerate(data_loader): # Train discriminator with real data real_inputs = Variable(inputs) real_labels = Variable(labels) real_labels = real_labels.view(real_labels.size(0), 1) real_inputs = torch.cat((real_inputs, real_labels), 1) real_outputs = self.discriminator(real_inputs) real_loss = nn.BCELoss()(real_outputs, torch.ones(real_outputs.size())) # Train discriminator with fake data noise = Variable(torch.randn(inputs.size(0), self.generator.input_dim)) fake_labels = Variable(torch.LongTensor(inputs.size(0)).random_(0, 10)) fake_labels = fake_labels.view(fake_labels.size(0), 1) fake_inputs = self.generator(torch.cat((noise, fake_labels.float()), 1)) fake_inputs = torch.cat((fake_inputs, fake_labels), 1) fake_outputs = self.discriminator(fake_inputs) fake_loss = nn.BCELoss()(fake_outputs, torch.zeros(fake_outputs.size())) # Backpropagate and update weights for discriminator discriminator_loss = real_loss + fake_loss self.discriminator.zero_grad() discriminator_loss.backward() self.optimizer_D.step() # Train generator noise = Variable(torch.randn(inputs.size(0), self.generator.input_dim)) fake_labels = Variable(torch.LongTensor(inputs.size(0)).random_(0,

2023-02-17 上传
其中，ConditionalGAN 类接受输入维度 input_dim、输出维度 output_dim、特征数 num_filters 和学习率 learning_rate。train 方法则接受数据加载器 data_loader 和训练轮数 num_epochs，用于训练模型。

class NeuralNetwork: def __init__(self, layers_strcuture, print_cost = False): self.layers_strcuture = layers_strcuture self.layers_num = len(layers_strcuture) self.param_layers_num = self.layers_num - 1 self.learning_rate = 0.0618 self.num_iterations = 2000 self.x = None self.y = None self.w = dict() self.b = dict() self.costs = [] self.print_cost = print_cost self.init_w_and_b() def set_learning_rate(self,learning_rate): self.learning_rate=learning_rate def set_num_iterations(self, num_iterations): self.num_iterations = num_iterations def set_xy(self, input, expected_output): self.x = input self.y = expected_output

2023-06-07 上传
这段代码定义了一个名为Neural...该类还包含了一些其他方法，包括set_learning_rate()、set_num_iterations()和set_xy()等，用于设置神经网络的学习率、迭代次数和输入数据等。这些方法可以在实例化该类后进行调用。

self.learning_rate = tf.train.exponential_decay( self.initial_learning_rate, self.global_step, self.decay_steps, self.decay_rate, self.staircase, name='learning_rate')是什么意思

2023-03-28 上传
其中，self.initial_learning_rate表示初始学习率，self.global_step表示训练步骤数，self.decay_steps表示学习率衰减的步骤数，self.decay_rate表示学习率衰减的速率，self.staircase表示是否按照阶梯型下降学习率...
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