python - 样本数量不一致意味着什么？

我正在使用scikit的逻辑回归，但我不断收到消息：

Found input variables with inconsistent numbers of samples: [90000, 5625]

在下面的代码中，我删除了其中包含文本的列，然后将日期分为训练和测试集。

import numpy as np
import pandas as pd
import matplotlib
import matplotlib.pyplot as plt
from scipy import stats
from sklearn import datasets, linear_model
from sklearn.model_selection import train_test_split

dataset = pd.read_csv("/Users/An/Desktop/data/telco.csv", na_values = ' ')
dataset = dataset.dropna(axis = 0)

dataset = dataset.replace({'Yes':1, 'Fiber optic': 1, 'DSL':1, 'No':0, 'No phone service':0, 'No internet service':0})
dataset = dataset.drop('Contract', axis  =1)
dataset = dataset.drop('PaymentMethod',axis  =1)
dataset = dataset.drop('customerID',axis  =1)
dataset = dataset.drop('gender',axis  =1)

for i in list(['tenure', 'MonthlyCharges', 'TotalCharges']):
    sd = np.std(dataset[i])
    mean = np.mean(dataset[i])
    dataset[i] = (dataset[i] - mean) / sd

total = pd.DataFrame(dataset)
data_train, data_test = train_test_split(total, test_size=0.2)
data_train = data_train.values
data_test = data_test.values

from sklearn.linear_model import LogisticRegression

clf = LogisticRegression(C=1e9)
clf = clf.fit(data_train[:,0:16], data_train[:,16])
print clf.intercept_, clf.coef_

有人可以解释该错误消息的含义，并帮助我弄清楚为什么得到此错误消息吗？

最佳答案

在最后第二行中，data_train.reshape(-1, 1)引起了您的问题。删除reshape将对您有利。

原因

LogisticRegression.fit期望x和y具有相同的shape[0]，但是您正在将x从(n, m)重塑为(n*m, 1)。

这是复制的形状：

import numpy as np

df = np.ndarray((2000,10))
x, y  = df[:, 2:9], df[:, 9]
x.shape, y.shape # << what you should give to `clf.fit`
# ((2000, 7), (2000, ))

x.reshape(-1, 1).shape, y.shape # << what you ARE giving to `clf.fit`,
# ((14000, 1), (2000,))         # << which is causing the problem

关于python - 样本数量不一致意味着什么？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/54401576/