1. 采用Python编程语言自己实现StandardScaler和MinMaxScaler这两种数据标准化方法,并用于乳腺癌数据的分类。 要求模型预测的准确率结果必须与以下sklearn的一样: from sklearn.datasets import load_breast_cancer from sklearn.model_selection import train_test_split cancer = load_breast_cancer() X = cancer.data y = cancer.target X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0, test_size=0.3) from sklearn.preprocessing import MinMaxScaler from sklearn.preprocessing import StandardScaler scaler = StandardScaler() #scaler = MinMaxScaler() scaler.fit(X_train) X_train_scaled = scaler.transform(X_train) X_test_scaled = scaler.transform(X_test) from sklearn.linear_model import LogisticRegression logreg=LogisticRegression() logreg.fit(X_train_scaled, y_train) y_pred = logreg.predict(X_test_scaled) from sklearn.metrics import accuracy_score accuracy_score(y_test, y_pred)
时间: 2023-12-24 22:12:17 浏览: 109
好的,这是一个很好的问题!数据标准化是数据预处理中非常重要的一步,可以帮助我们更好地训练模型。下面是我为你提供的Python代码,可以自己实现StandardScaler和MinMaxScaler这两种数据标准化方法,并用于乳腺癌数据的分类。
```
import numpy as np
class StandardScaler:
def __init__(self):
self.mean_ = None
self.std_ = None
def fit(self, X):
self.mean_ = np.mean(X, axis=0)
self.std_ = np.std(X, axis=0)
def transform(self, X):
return (X - self.mean_) / self.std_
class MinMaxScaler:
def __init__(self):
self.min_ = None
self.max_ = None
def fit(self, X):
self.min_ = np.min(X, axis=0)
self.max_ = np.max(X, axis=0)
def transform(self, X):
return (X - self.min_) / (self.max_ - self.min_)
# 加载乳腺癌数据
from sklearn.datasets import load_breast_cancer
from sklearn.model_selection import train_test_split
cancer = load_breast_cancer()
X = cancer.data
y = cancer.target
# 划分训练集和测试集
X_train, X_test, y_train, y_test = train_test_split(X, y, random_state=0, test_size=0.3)
# 使用自己实现的StandardScaler进行数据标准化
scaler = StandardScaler()
scaler.fit(X_train)
X_train_scaled = scaler.transform(X_train)
X_test_scaled = scaler.transform(X_test)
# 使用逻辑回归进行分类
from sklearn.linear_model import LogisticRegression
logreg = LogisticRegression()
logreg.fit(X_train_scaled, y_train)
y_pred = logreg.predict(X_test_scaled)
# 计算准确率
from sklearn.metrics import accuracy_score
print("Accuracy score:", accuracy_score(y_test, y_pred))
```
这段代码中,我们分别实现了StandardScaler和MinMaxScaler这两种数据标准化方法,并且使用逻辑回归进行分类。最后,我们计算了模型预测的准确率结果,应该与sklearn的一样。
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