Python的scipy chisquare返回的值与R chisquare不同

Question

我正在尝试使用scipy.stats.chisquare。我已经构建了一个玩具示例：

In [1]: import scipy.stats as sps

In [2]: import numpy as np

In [3]: sps.chisquare(np.array([38,27,23,17,11,4]), np.array([98, 100, 80, 85,60,23]))
Out[11]: (240.74951271813072, 5.302429887719704e-50)

同样的例子在R中返回：

> chisq.test(matrix(c(38,27,23,17,11,4,98,100,80,85,60,23), ncol=2))

Pearson's Chi-squared test

data:  matrix(c(38, 27, 23, 17, 11, 4, 98, 100, 80, 85, 60, 23), ncol = 2)
X-squared = 7.0762, df = 5, p-value = 0.215

我做错了什么？

谢谢

- gc5

Answer 1

对于这个chisq.test调用，其Python等价函数为chi2_contingency：

此函数计算观察到的列联表中的频数是否独立的卡方值和p值。

>>> arr = np.array([38,27,23,17,11,4,98,100,80,85,60,23]).reshape(2,-1)
>>> arr
array([[ 38,  27,  23,  17,  11,   4],
       [ 98, 100,  80,  85,  60,  23]])
>>> chi2, p, dof, expected = scipy.stats.chi2_contingency(arr)
>>> chi2, p, dof
(7.0762165124844367, 0.21503342516989818, 5)

- alko