R数据操纵和卡方测试

Question

我有一个数据框架：

gender   group   count    total
female    A       8        10
female    B       23       30
female    C       22       25
male      A       18       28
male      B       23       30
male      C       40       70

如何处理数据并为性别之间的每个组应用卡方检验？

Answer 1

首先使用DPUT函数来使您的数据变得容易复制

dput(dat)
structure(list(gender = c("female", "female", "female", "male",
"male", "male"), group = c("A", "B", "C", "A", "B", "C"), count = c(8L,
23L, 22L, 18L, 23L, 40L), total = c(10L, 30L, 25L, 28L, 30L,
70L)), class = "data.frame", row.names = c(NA, -6L)).   

，然后您可以通过组（或性别）来使用BY BY函数，

by(dat, dat$group, function(x) chisq.test(data.frame(x$count, x$total)))
dat$group: A

Pearson's Chi-squared test with Yates' continuity correction

data:  data.frame(x$count, x$total)
X-squared = 0.011266, df = 1, p-value = 0.9155

---

dat$group: B

Pearson's Chi-squared test

data:  data.frame(x$count, x$total)
X-squared = 0, df = 1, p-value = 1

---

dat$group: C

Pearson's Chi-squared test with Yates' continuity correction

data:  data.frame(x$count, x$total)
X-squared = 1.0981, df = 1, p-value = 0.2947

值得确保其测试确切地进行测试，但通过查看2*2矩阵此方法创建：

例如

> by(dat, dat$group, function(x)data.frame(x$count, x$total))[1]
$A
  x.count x.total
1       8      10
2      18      28