data_scaler = preprocessing.scale(data)

This line of code scales the data using the z-score normalization method. It standardizes the data by subtracting the mean of each feature and dividing by its standard deviation to bring all the features to the same scale. This is useful when working with datasets that have features with different units or scales. The scaled data will have a mean of zero and a standard deviation of one, making it easier to compare and analyze different features. The scaled data is stored in the variable "data_scaler".

相关问题

import tensorflow as tf import numpy as np import matplotlib.pyplot as plt import pandas as pd from sklearn.utils import shuffle from sklearn.preprocessing import scale df = pd.read_csv("C:\\boston.csv",header=0) ds = df.values from sklearn.datasets import load_boston boston = load_boston() X = boston.data y = boston.target from sklearn.model_selection import train_test_split X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42) from sklearn.preprocessing import StandardScaler scaler = StandardScaler() X_train = scaler.fit_transform(X_train) X_test = scaler.transform(X_test) from tensorflow.keras.models import Sequential from tensorflow.keras.layers import Dense model = Sequential([ Dense(64, activation='relu', input_shape=(X_train.shape[1],)), Dense(64, activation='relu'), Dense(64, activation='relu'), Dense(1) ]) model.compile(loss='mean_squared_error', optimizer='adam') history = model.fit(X_train, y_train, validation_split=0.1, epochs=100, batch_size=32) from sklearn.metrics import mean_squared_error y_pred = model.predict(x_test)mse = mean_squared_error(y_test, y_pred)print('MSE:’, mse) import matplotlib.pyplot as plt plt.plot(history.history['accuracy'], label='train') plt.plot(history.history['val_accuracy'], label='validation') plt.legend() plt.show()

这段代码使用TensorFlow和Keras实现了一个神经网络模型，用于预测波士顿房价。以下是代码的解释：

首先，导入必要的库和模块：

import tensorflow as tf
import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
from sklearn.utils import shuffle
from sklearn.preprocessing import scale

然后，读取波士顿房价数据集并对其进行预处理：

df = pd.read_csv("C:\\boston.csv",header=0)
ds = df.values

接着，从sklearn.datasets模块中加载波士顿房价数据集，并将其分为训练集和测试集：

from sklearn.datasets import load_boston
boston = load_boston()
X = boston.data
y = boston.target
from sklearn.model_selection import train_test_split
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42)

对训练集和测试集进行标准化处理：

from sklearn.preprocessing import StandardScaler
scaler = StandardScaler()
X_train = scaler.fit_transform(X_train)
X_test = scaler.transform(X_test)

定义一个包含4个Dense层的神经网络模型：

from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Dense

model = Sequential([
    Dense(64, activation='relu', input_shape=(X_train.shape[1],)),
    Dense(64, activation='relu'),
    Dense(64, activation='relu'),
    Dense(1)
])

编译模型并训练：

model.compile(loss='mean_squared_error', optimizer='adam')

history = model.fit(X_train, y_train, validation_split=0.1, epochs=100, batch_size=32)

使用模型对测试集进行预测，并计算均方误差：

from sklearn.metrics import mean_squared_error
y_pred = model.predict(x_test)
mse = mean_squared_error(y_test, y_pred)
print('MSE:’, mse)

最后，绘制模型的训练和验证准确率曲线：

import matplotlib.pyplot as plt

plt.plot(history.history['accuracy'], label='train')
plt.plot(history.history['val_accuracy'], label='validation')

plt.legend()

plt.show()

from sklearn.metrics import RocCurveDisplay from sklearn.model_selection import train_test_split from sklearn.metrics import confusion_matrix,accuracy_score from sklearn.preprocessing import StandardScaler from sklearn.linear_model import LogisticRegression from sklearn import tree from sklearn.decomposition import PCA import matplotlib.pyplot as plt from sklearn.tree import DecisionTreeClassifier data = pd.read_csv("C:\\Users\\sa'y\\Desktop\\framinghamData(1).csv") X = data[["sysBP", "diaBP", "age", "totChol", "BMI", "heartRate", "glucose"]] y = data[['TenYearCHD']] new_data = pd.concat([X, y], axis=1) print(new_data.head()) scaler = StandardScaler() X_scaled = scaler.fit_transform(X) print(X_scaled) corr = new_data.corr(method='pearson') sns.heatmap(corr, annot=True, cmap='coolwarm') plt.show() pca = PCA(n_components=7) newX = pca.fit_transform(X) x_data = ['PC1','PC2','PC3','PC4','PC5','PC6','PC7'] y_data = np.around(pca.explained_variance_ratio_, 2) plt.bar(x=x_data, height=y_data,color='steelblue', alpha=0.8) plt.show() 在上述代码基础上，请给出下一步的代码，要求是： 计算所有主成分之间的皮尔逊相关系数，并用热图Heatmap的形式展示出来

import numpy as np
from matplotlib import pyplot as plt
import seaborn as sns

# 计算所有主成分之间的皮尔逊相关系数
corr_pca = np.corrcoef(newX.T)

# Heatmap展示相关系数
sns.set(font_scale=1)
sns.heatmap(corr_pca, cbar=True, annot=True, square=True, fmt='.2f', annot_kws={'size': 10}, yticklabels=x_data, xticklabels=x_data)
plt.savefig('corr_pca_heatmap.png')
plt.show()